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 changind 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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Language: | English |
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ftuloxford:oai:ora.ox.ac.uk:uuid:e72a0fcd-4877-4b47-bb9c-9b7eafd9ef8b 2023-05-15T13:34:15+02:00 Stability of ice-sheet grounding lines Katz, R Worster, M 2016-07-29 https://doi.org/10.1098/rspa.2009.0434 https://ora.ox.ac.uk/objects/uuid:e72a0fcd-4877-4b47-bb9c-9b7eafd9ef8b eng eng Royal Society Publishing doi:10.1098/rspa.2009.0434 https://ora.ox.ac.uk/objects/uuid:e72a0fcd-4877-4b47-bb9c-9b7eafd9ef8b https://doi.org/10.1098/rspa.2009.0434 info:eu-repo/semantics/embargoedAccess Earth sciences Journal article 2016 ftuloxford https://doi.org/10.1098/rspa.2009.0434 2022-06-28T20:26:42Z 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 changind 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. Out 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 based 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 feauture 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 occuring at the Pine Island glacier. Article in Journal/Newspaper Antarc* Antarctic Ice Sheet Ice Shelf Pine Island Glacier ORA - Oxford University Research Archive 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 |
ORA - Oxford University Research Archive |
op_collection_id |
ftuloxford |
language |
English |
topic |
Earth sciences |
spellingShingle |
Earth sciences Katz, R Worster, M Stability of ice-sheet grounding lines |
topic_facet |
Earth sciences |
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 changind 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. Out 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 based 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 feauture 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 occuring at the Pine Island glacier. |
format |
Article in Journal/Newspaper |
author |
Katz, R Worster, M |
author_facet |
Katz, R Worster, M |
author_sort |
Katz, R |
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 |
Royal Society Publishing |
publishDate |
2016 |
url |
https://doi.org/10.1098/rspa.2009.0434 https://ora.ox.ac.uk/objects/uuid:e72a0fcd-4877-4b47-bb9c-9b7eafd9ef8b |
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_relation |
doi:10.1098/rspa.2009.0434 https://ora.ox.ac.uk/objects/uuid:e72a0fcd-4877-4b47-bb9c-9b7eafd9ef8b https://doi.org/10.1098/rspa.2009.0434 |
op_rights |
info:eu-repo/semantics/embargoedAccess |
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_ |
1766050730699915264 |