Sensitivity of Pine Island Glacier, West Antarctica, to changes in ice-shelf and basal conditions: a model study
We use a finite-element model of coupled ice-stream/ice-shelf flow to study the sensitivity of Pine Island Glacier, West Antarctica, to changes in ice-shelf and basal conditions. By tuning a softening coefficient of the ice along the glacier margins, and a basal friction coefficient controlling the...
Published in: | Journal of Glaciology |
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eScholarship, University of California
2002
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Online Access: | https://escholarship.org/uc/item/2t18h2fr https://escholarship.org/content/qt2t18h2fr/qt2t18h2fr.pdf https://doi.org/10.3189/172756502781831061 |
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ftcdlib:oai:escholarship.org:ark:/13030/qt2t18h2fr 2024-09-15T17:46:53+00:00 Sensitivity of Pine Island Glacier, West Antarctica, to changes in ice-shelf and basal conditions: a model study Schmeltz, Marjorie Rignot, Eric Dupont, Todd K MacAyeal, Douglas R 552 - 558 2002-01-01 application/pdf https://escholarship.org/uc/item/2t18h2fr https://escholarship.org/content/qt2t18h2fr/qt2t18h2fr.pdf https://doi.org/10.3189/172756502781831061 unknown eScholarship, University of California qt2t18h2fr https://escholarship.org/uc/item/2t18h2fr https://escholarship.org/content/qt2t18h2fr/qt2t18h2fr.pdf doi:10.3189/172756502781831061 CC-BY Journal of Glaciology, vol 48, iss 163 Physical Geography and Environmental Geoscience Meteorology & Atmospheric Sciences article 2002 ftcdlib https://doi.org/10.3189/172756502781831061 2024-06-28T06:28:20Z We use a finite-element model of coupled ice-stream/ice-shelf flow to study the sensitivity of Pine Island Glacier, West Antarctica, to changes in ice-shelf and basal conditions. By tuning a softening coefficient of the ice along the glacier margins, and a basal friction coefficient controlling the distribution of basal shear stress underneath the ice stream, we are able to match model velocity to that observed with interferometric synthetic aperture radar (InSAR). We use the model to investigate the effect of small perturbations on ice flow. We find that a 5.5 13% reduction in our initial ice-shelf area increases the glacier velocity by 3.5 10% at the grounding line. The removal of the entire ice shelf increases the grounding-line velocity by > 70%. The changes in velocity associated with ice-shelf reduction are felt several tens of km inland. Alternatively, a 5% reduction in basal shear stress increases the glacier velocity by 13% at the grounding line. By contrast, softening of the glacier side margins would have to be increased a lot more to produce a comparable change in ice velocity. Hence, both the ice-shelf buttressing and the basal shear stress contribute significant resistance to the flow of Pine Island Glacier. Article in Journal/Newspaper Antarc* Antarctica Ice Shelf Journal of Glaciology Pine Island Pine Island Glacier West Antarctica University of California: eScholarship Journal of Glaciology 48 163 552 558 |
institution |
Open Polar |
collection |
University of California: eScholarship |
op_collection_id |
ftcdlib |
language |
unknown |
topic |
Physical Geography and Environmental Geoscience Meteorology & Atmospheric Sciences |
spellingShingle |
Physical Geography and Environmental Geoscience Meteorology & Atmospheric Sciences Schmeltz, Marjorie Rignot, Eric Dupont, Todd K MacAyeal, Douglas R Sensitivity of Pine Island Glacier, West Antarctica, to changes in ice-shelf and basal conditions: a model study |
topic_facet |
Physical Geography and Environmental Geoscience Meteorology & Atmospheric Sciences |
description |
We use a finite-element model of coupled ice-stream/ice-shelf flow to study the sensitivity of Pine Island Glacier, West Antarctica, to changes in ice-shelf and basal conditions. By tuning a softening coefficient of the ice along the glacier margins, and a basal friction coefficient controlling the distribution of basal shear stress underneath the ice stream, we are able to match model velocity to that observed with interferometric synthetic aperture radar (InSAR). We use the model to investigate the effect of small perturbations on ice flow. We find that a 5.5 13% reduction in our initial ice-shelf area increases the glacier velocity by 3.5 10% at the grounding line. The removal of the entire ice shelf increases the grounding-line velocity by > 70%. The changes in velocity associated with ice-shelf reduction are felt several tens of km inland. Alternatively, a 5% reduction in basal shear stress increases the glacier velocity by 13% at the grounding line. By contrast, softening of the glacier side margins would have to be increased a lot more to produce a comparable change in ice velocity. Hence, both the ice-shelf buttressing and the basal shear stress contribute significant resistance to the flow of Pine Island Glacier. |
format |
Article in Journal/Newspaper |
author |
Schmeltz, Marjorie Rignot, Eric Dupont, Todd K MacAyeal, Douglas R |
author_facet |
Schmeltz, Marjorie Rignot, Eric Dupont, Todd K MacAyeal, Douglas R |
author_sort |
Schmeltz, Marjorie |
title |
Sensitivity of Pine Island Glacier, West Antarctica, to changes in ice-shelf and basal conditions: a model study |
title_short |
Sensitivity of Pine Island Glacier, West Antarctica, to changes in ice-shelf and basal conditions: a model study |
title_full |
Sensitivity of Pine Island Glacier, West Antarctica, to changes in ice-shelf and basal conditions: a model study |
title_fullStr |
Sensitivity of Pine Island Glacier, West Antarctica, to changes in ice-shelf and basal conditions: a model study |
title_full_unstemmed |
Sensitivity of Pine Island Glacier, West Antarctica, to changes in ice-shelf and basal conditions: a model study |
title_sort |
sensitivity of pine island glacier, west antarctica, to changes in ice-shelf and basal conditions: a model study |
publisher |
eScholarship, University of California |
publishDate |
2002 |
url |
https://escholarship.org/uc/item/2t18h2fr https://escholarship.org/content/qt2t18h2fr/qt2t18h2fr.pdf https://doi.org/10.3189/172756502781831061 |
op_coverage |
552 - 558 |
genre |
Antarc* Antarctica Ice Shelf Journal of Glaciology Pine Island Pine Island Glacier West Antarctica |
genre_facet |
Antarc* Antarctica Ice Shelf Journal of Glaciology Pine Island Pine Island Glacier West Antarctica |
op_source |
Journal of Glaciology, vol 48, iss 163 |
op_relation |
qt2t18h2fr https://escholarship.org/uc/item/2t18h2fr https://escholarship.org/content/qt2t18h2fr/qt2t18h2fr.pdf doi:10.3189/172756502781831061 |
op_rights |
CC-BY |
op_doi |
https://doi.org/10.3189/172756502781831061 |
container_title |
Journal of Glaciology |
container_volume |
48 |
container_issue |
163 |
container_start_page |
552 |
op_container_end_page |
558 |
_version_ |
1810495311645245440 |