Marine ice sheet stability
Abstract We examine the stability of two-dimensional marine ice sheets in steady state. The dynamics of marine ice sheets is described by a viscous thin-film model with two Stefan-type boundary conditions at the moving boundary or ‘grounding line’ that marks the transition from grounded to floating...
Published in: | Journal of Fluid Mechanics |
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Language: | English |
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Cambridge University Press (CUP)
2012
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Online Access: | http://dx.doi.org/10.1017/jfm.2012.43 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022112012000432 |
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crcambridgeupr:10.1017/jfm.2012.43 2024-06-23T07:53:48+00:00 Marine ice sheet stability Schoof, Christian 2012 http://dx.doi.org/10.1017/jfm.2012.43 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022112012000432 en eng Cambridge University Press (CUP) https://www.cambridge.org/core/terms Journal of Fluid Mechanics volume 698, page 62-72 ISSN 0022-1120 1469-7645 journal-article 2012 crcambridgeupr https://doi.org/10.1017/jfm.2012.43 2024-06-05T04:04:41Z Abstract We examine the stability of two-dimensional marine ice sheets in steady state. The dynamics of marine ice sheets is described by a viscous thin-film model with two Stefan-type boundary conditions at the moving boundary or ‘grounding line’ that marks the transition from grounded to floating ice. One of these boundary conditions constrains ice thickness to be at a local critical value for flotation, which depends on depth to bedrock at the grounding line. The other condition sets ice flux as a function of ice thickness at the grounding line. Depending on the shape of the bedrock, multiple equilibria may be possible. Using a linear stability analysis, we confirm a long-standing heuristic argument that asserts that the stability of these equilibria is determined by a simple mass balance consideration. If an advance in the grounding line away from its steady-state position leads to a net mass gain, the steady state is unstable, and stable otherwise. This also confirms that grounding lines can only be stable in positions where bedrock slopes downwards sufficiently steeply. Article in Journal/Newspaper Ice Sheet Cambridge University Press Journal of Fluid Mechanics 698 62 72 |
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Open Polar |
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Cambridge University Press |
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crcambridgeupr |
language |
English |
description |
Abstract We examine the stability of two-dimensional marine ice sheets in steady state. The dynamics of marine ice sheets is described by a viscous thin-film model with two Stefan-type boundary conditions at the moving boundary or ‘grounding line’ that marks the transition from grounded to floating ice. One of these boundary conditions constrains ice thickness to be at a local critical value for flotation, which depends on depth to bedrock at the grounding line. The other condition sets ice flux as a function of ice thickness at the grounding line. Depending on the shape of the bedrock, multiple equilibria may be possible. Using a linear stability analysis, we confirm a long-standing heuristic argument that asserts that the stability of these equilibria is determined by a simple mass balance consideration. If an advance in the grounding line away from its steady-state position leads to a net mass gain, the steady state is unstable, and stable otherwise. This also confirms that grounding lines can only be stable in positions where bedrock slopes downwards sufficiently steeply. |
format |
Article in Journal/Newspaper |
author |
Schoof, Christian |
spellingShingle |
Schoof, Christian Marine ice sheet stability |
author_facet |
Schoof, Christian |
author_sort |
Schoof, Christian |
title |
Marine ice sheet stability |
title_short |
Marine ice sheet stability |
title_full |
Marine ice sheet stability |
title_fullStr |
Marine ice sheet stability |
title_full_unstemmed |
Marine ice sheet stability |
title_sort |
marine ice sheet stability |
publisher |
Cambridge University Press (CUP) |
publishDate |
2012 |
url |
http://dx.doi.org/10.1017/jfm.2012.43 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022112012000432 |
genre |
Ice Sheet |
genre_facet |
Ice Sheet |
op_source |
Journal of Fluid Mechanics volume 698, page 62-72 ISSN 0022-1120 1469-7645 |
op_rights |
https://www.cambridge.org/core/terms |
op_doi |
https://doi.org/10.1017/jfm.2012.43 |
container_title |
Journal of Fluid Mechanics |
container_volume |
698 |
container_start_page |
62 |
op_container_end_page |
72 |
_version_ |
1802645630695243776 |