Hysteretic evolution of ice rises and ice rumples in response to variations in sea level
Ice rises and ice rumples are locally grounded features found in coastal Antarctica and are surrounded by otherwise freely floating ice shelves. An ice rise has an independent flow regime, whereas the flow regime of an ice rumple conforms to that of the ice shelf and merely slows the flow of ice. In...
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ftcopernicus:oai:publications.copernicus.org:tc102322 2023-05-15T13:38:41+02:00 Hysteretic evolution of ice rises and ice rumples in response to variations in sea level Henry, A. Clara J. Drews, Reinhard Schannwell, Clemens Višnjević, Vjeran 2022-09-29 application/pdf https://doi.org/10.5194/tc-16-3889-2022 https://tc.copernicus.org/articles/16/3889/2022/ eng eng doi:10.5194/tc-16-3889-2022 https://tc.copernicus.org/articles/16/3889/2022/ eISSN: 1994-0424 Text 2022 ftcopernicus https://doi.org/10.5194/tc-16-3889-2022 2022-10-03T16:22:42Z Ice rises and ice rumples are locally grounded features found in coastal Antarctica and are surrounded by otherwise freely floating ice shelves. An ice rise has an independent flow regime, whereas the flow regime of an ice rumple conforms to that of the ice shelf and merely slows the flow of ice. In both cases, local highs in the bathymetry are in contact with the ice shelf from below, thereby regulating the large-scale ice flow, with implications for the upstream continental grounding line position. This buttressing effect, paired with the suitability of ice rises as a climate archive, necessitates a better understanding of the transition between ice rise and ice rumple, their evolution in response to a change in sea level, and their dynamic interaction with the surrounding ice shelf. We investigate this behaviour using a three-dimensional full Stokes ice flow model with idealised ice rises and ice rumples. The simulations span end-member basal friction scenarios of almost stagnant and fully sliding ice at the ice–bed interface. We analyse the coupling with the surrounding ice shelf by comparing the deviations between the non-local full Stokes surface velocities and the local shallow ice approximation (SIA). Deviations are generally high at the ice divides and small on the lee sides. On the stoss side, where ice rise and ice shelf have opposing flow directions, deviations can be significant. Differences are negligible in the absence of basal sliding where the corresponding steady-state ice rise is larger and develops a fully independent flow regime that is well described by SIA. When sea level is increased, and a transition from ice rise to ice rumple is approached, the divide migration is more abrupt the higher the basal friction. In each scenario, the transition occurs after the stoss-side grounding line has moved over the bed high and is positioned on a retrograde slope. We identify a hysteretic response of ice rises and ice rumples to changes in sea level, with grounded area being larger in a ... Text Antarc* Antarctica Ice Shelf Ice Shelves Copernicus Publications: E-Journals The Cryosphere 16 9 3889 3905 |
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Open Polar |
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Copernicus Publications: E-Journals |
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ftcopernicus |
language |
English |
description |
Ice rises and ice rumples are locally grounded features found in coastal Antarctica and are surrounded by otherwise freely floating ice shelves. An ice rise has an independent flow regime, whereas the flow regime of an ice rumple conforms to that of the ice shelf and merely slows the flow of ice. In both cases, local highs in the bathymetry are in contact with the ice shelf from below, thereby regulating the large-scale ice flow, with implications for the upstream continental grounding line position. This buttressing effect, paired with the suitability of ice rises as a climate archive, necessitates a better understanding of the transition between ice rise and ice rumple, their evolution in response to a change in sea level, and their dynamic interaction with the surrounding ice shelf. We investigate this behaviour using a three-dimensional full Stokes ice flow model with idealised ice rises and ice rumples. The simulations span end-member basal friction scenarios of almost stagnant and fully sliding ice at the ice–bed interface. We analyse the coupling with the surrounding ice shelf by comparing the deviations between the non-local full Stokes surface velocities and the local shallow ice approximation (SIA). Deviations are generally high at the ice divides and small on the lee sides. On the stoss side, where ice rise and ice shelf have opposing flow directions, deviations can be significant. Differences are negligible in the absence of basal sliding where the corresponding steady-state ice rise is larger and develops a fully independent flow regime that is well described by SIA. When sea level is increased, and a transition from ice rise to ice rumple is approached, the divide migration is more abrupt the higher the basal friction. In each scenario, the transition occurs after the stoss-side grounding line has moved over the bed high and is positioned on a retrograde slope. We identify a hysteretic response of ice rises and ice rumples to changes in sea level, with grounded area being larger in a ... |
format |
Text |
author |
Henry, A. Clara J. Drews, Reinhard Schannwell, Clemens Višnjević, Vjeran |
spellingShingle |
Henry, A. Clara J. Drews, Reinhard Schannwell, Clemens Višnjević, Vjeran Hysteretic evolution of ice rises and ice rumples in response to variations in sea level |
author_facet |
Henry, A. Clara J. Drews, Reinhard Schannwell, Clemens Višnjević, Vjeran |
author_sort |
Henry, A. Clara J. |
title |
Hysteretic evolution of ice rises and ice rumples in response to variations in sea level |
title_short |
Hysteretic evolution of ice rises and ice rumples in response to variations in sea level |
title_full |
Hysteretic evolution of ice rises and ice rumples in response to variations in sea level |
title_fullStr |
Hysteretic evolution of ice rises and ice rumples in response to variations in sea level |
title_full_unstemmed |
Hysteretic evolution of ice rises and ice rumples in response to variations in sea level |
title_sort |
hysteretic evolution of ice rises and ice rumples in response to variations in sea level |
publishDate |
2022 |
url |
https://doi.org/10.5194/tc-16-3889-2022 https://tc.copernicus.org/articles/16/3889/2022/ |
genre |
Antarc* Antarctica Ice Shelf Ice Shelves |
genre_facet |
Antarc* Antarctica Ice Shelf Ice Shelves |
op_source |
eISSN: 1994-0424 |
op_relation |
doi:10.5194/tc-16-3889-2022 https://tc.copernicus.org/articles/16/3889/2022/ |
op_doi |
https://doi.org/10.5194/tc-16-3889-2022 |
container_title |
The Cryosphere |
container_volume |
16 |
container_issue |
9 |
container_start_page |
3889 |
op_container_end_page |
3905 |
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1766109577517989888 |