Stability of ice-sheet grounding lines
Recent observations of the West Antarctic Ice Sheet document rapid changes in the mass balance of its component glaciers. These observations raise the question of whether changing climatic conditions have triggered a dynamical instability in the ice-sheet–ice-shelf system. The dynamics of marine ice...
Published in: | Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences |
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crroyalsociety:10.1098/rspa.2009.0434 2024-06-02T07:57:37+00:00 Stability of ice-sheet grounding lines Katz, Richard F. Worster, M. Grae 2010 http://dx.doi.org/10.1098/rspa.2009.0434 https://royalsocietypublishing.org/doi/pdf/10.1098/rspa.2009.0434 https://royalsocietypublishing.org/doi/full-xml/10.1098/rspa.2009.0434 en eng The Royal Society https://royalsociety.org/journals/ethics-policies/data-sharing-mining/ Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences volume 466, issue 2118, page 1597-1620 ISSN 1364-5021 1471-2946 journal-article 2010 crroyalsociety https://doi.org/10.1098/rspa.2009.0434 2024-05-07T14:16:33Z Recent observations of the West Antarctic Ice Sheet document rapid changes in the mass balance of its component glaciers. These observations raise the question of whether changing climatic conditions have triggered a dynamical instability in the ice-sheet–ice-shelf system. The dynamics of marine ice sheets are sensitive to grounding-line position and variation, characteristics that are poorly captured by most current models. We present a theory for grounding-line dynamics in three spatial dimensions and time. Our theory is based on a balance of forces across the grounding line; it is expressed as a differential equation that is analogous to the canonical Stefan condition. We apply this theory to the question of grounding-line stability under conditions of retrograde bed slope in a suite of calculations with different basal topography. A subset of these have basal topography inspired by the Pine Island glacier, where basal depth varies in both the along-flow and across-flow directions. Our results indicate that unstable retreat of the grounding line over retrograde beds is a robust feature of models that evolve based on force balance at the grounding line. We conclude, based on our simplified model, that unstable grounding-line recession may already be occurring at the Pine Island glacier. Article in Journal/Newspaper Antarc* Antarctic Ice Sheet Ice Shelf Pine Island Glacier The Royal Society Antarctic West Antarctic Ice Sheet Pine Island Glacier ENVELOPE(-101.000,-101.000,-75.000,-75.000) Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 466 2118 1597 1620 |
institution |
Open Polar |
collection |
The Royal Society |
op_collection_id |
crroyalsociety |
language |
English |
description |
Recent observations of the West Antarctic Ice Sheet document rapid changes in the mass balance of its component glaciers. These observations raise the question of whether changing climatic conditions have triggered a dynamical instability in the ice-sheet–ice-shelf system. The dynamics of marine ice sheets are sensitive to grounding-line position and variation, characteristics that are poorly captured by most current models. We present a theory for grounding-line dynamics in three spatial dimensions and time. Our theory is based on a balance of forces across the grounding line; it is expressed as a differential equation that is analogous to the canonical Stefan condition. We apply this theory to the question of grounding-line stability under conditions of retrograde bed slope in a suite of calculations with different basal topography. A subset of these have basal topography inspired by the Pine Island glacier, where basal depth varies in both the along-flow and across-flow directions. Our results indicate that unstable retreat of the grounding line over retrograde beds is a robust feature of models that evolve based on force balance at the grounding line. We conclude, based on our simplified model, that unstable grounding-line recession may already be occurring at the Pine Island glacier. |
format |
Article in Journal/Newspaper |
author |
Katz, Richard F. Worster, M. Grae |
spellingShingle |
Katz, Richard F. Worster, M. Grae Stability of ice-sheet grounding lines |
author_facet |
Katz, Richard F. Worster, M. Grae |
author_sort |
Katz, Richard F. |
title |
Stability of ice-sheet grounding lines |
title_short |
Stability of ice-sheet grounding lines |
title_full |
Stability of ice-sheet grounding lines |
title_fullStr |
Stability of ice-sheet grounding lines |
title_full_unstemmed |
Stability of ice-sheet grounding lines |
title_sort |
stability of ice-sheet grounding lines |
publisher |
The Royal Society |
publishDate |
2010 |
url |
http://dx.doi.org/10.1098/rspa.2009.0434 https://royalsocietypublishing.org/doi/pdf/10.1098/rspa.2009.0434 https://royalsocietypublishing.org/doi/full-xml/10.1098/rspa.2009.0434 |
long_lat |
ENVELOPE(-101.000,-101.000,-75.000,-75.000) |
geographic |
Antarctic West Antarctic Ice Sheet Pine Island Glacier |
geographic_facet |
Antarctic West Antarctic Ice Sheet Pine Island Glacier |
genre |
Antarc* Antarctic Ice Sheet Ice Shelf Pine Island Glacier |
genre_facet |
Antarc* Antarctic Ice Sheet Ice Shelf Pine Island Glacier |
op_source |
Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences volume 466, issue 2118, page 1597-1620 ISSN 1364-5021 1471-2946 |
op_rights |
https://royalsociety.org/journals/ethics-policies/data-sharing-mining/ |
op_doi |
https://doi.org/10.1098/rspa.2009.0434 |
container_title |
Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences |
container_volume |
466 |
container_issue |
2118 |
container_start_page |
1597 |
op_container_end_page |
1620 |
_version_ |
1800740803506601984 |