Persistence and variability of ice-stream grounding lines on retrograde bed slopes
In many ice streams, basal resistance varies in space and time due to the dynamically evolving properties of subglacial till. These variations can cause internally generated oscillations in ice-stream flow. However, the potential for such variations in basal properties is not considered by conventio...
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ftcopernicus:oai:publications.copernicus.org:tc49523 2023-05-15T13:54:27+02:00 Persistence and variability of ice-stream grounding lines on retrograde bed slopes Robel, Alexander A. Schoof, Christian Tziperman, Eli 2018-09-27 application/pdf https://doi.org/10.5194/tc-10-1883-2016 https://tc.copernicus.org/articles/10/1883/2016/ eng eng doi:10.5194/tc-10-1883-2016 https://tc.copernicus.org/articles/10/1883/2016/ eISSN: 1994-0424 Text 2018 ftcopernicus https://doi.org/10.5194/tc-10-1883-2016 2020-07-20T16:24:01Z In many ice streams, basal resistance varies in space and time due to the dynamically evolving properties of subglacial till. These variations can cause internally generated oscillations in ice-stream flow. However, the potential for such variations in basal properties is not considered by conventional theories of grounding-line stability on retrograde bed slopes, which assume that bed properties are static in time. Using a flow-line model, we show how internally generated, transient variations in ice-stream state interact with retrograde bed slopes. In contrast to predictions from the theory of the marine ice-sheet instability, our simulated grounding line is able to persist and reverse direction of migration on a retrograde bed when undergoing oscillations in the grounding-line position. In turn, the presence of a retrograde bed may also suppress or reduce the amplitude of internal oscillations in ice-stream state. We explore the physical mechanisms responsible for these behaviors and discuss the implications for observed grounding-line migration in West Antarctica. Text Antarc* Antarctica Ice Sheet West Antarctica Copernicus Publications: E-Journals West Antarctica The Cryosphere 10 4 1883 1896 |
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Open Polar |
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Copernicus Publications: E-Journals |
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ftcopernicus |
language |
English |
description |
In many ice streams, basal resistance varies in space and time due to the dynamically evolving properties of subglacial till. These variations can cause internally generated oscillations in ice-stream flow. However, the potential for such variations in basal properties is not considered by conventional theories of grounding-line stability on retrograde bed slopes, which assume that bed properties are static in time. Using a flow-line model, we show how internally generated, transient variations in ice-stream state interact with retrograde bed slopes. In contrast to predictions from the theory of the marine ice-sheet instability, our simulated grounding line is able to persist and reverse direction of migration on a retrograde bed when undergoing oscillations in the grounding-line position. In turn, the presence of a retrograde bed may also suppress or reduce the amplitude of internal oscillations in ice-stream state. We explore the physical mechanisms responsible for these behaviors and discuss the implications for observed grounding-line migration in West Antarctica. |
format |
Text |
author |
Robel, Alexander A. Schoof, Christian Tziperman, Eli |
spellingShingle |
Robel, Alexander A. Schoof, Christian Tziperman, Eli Persistence and variability of ice-stream grounding lines on retrograde bed slopes |
author_facet |
Robel, Alexander A. Schoof, Christian Tziperman, Eli |
author_sort |
Robel, Alexander A. |
title |
Persistence and variability of ice-stream grounding lines on retrograde bed slopes |
title_short |
Persistence and variability of ice-stream grounding lines on retrograde bed slopes |
title_full |
Persistence and variability of ice-stream grounding lines on retrograde bed slopes |
title_fullStr |
Persistence and variability of ice-stream grounding lines on retrograde bed slopes |
title_full_unstemmed |
Persistence and variability of ice-stream grounding lines on retrograde bed slopes |
title_sort |
persistence and variability of ice-stream grounding lines on retrograde bed slopes |
publishDate |
2018 |
url |
https://doi.org/10.5194/tc-10-1883-2016 https://tc.copernicus.org/articles/10/1883/2016/ |
geographic |
West Antarctica |
geographic_facet |
West Antarctica |
genre |
Antarc* Antarctica Ice Sheet West Antarctica |
genre_facet |
Antarc* Antarctica Ice Sheet West Antarctica |
op_source |
eISSN: 1994-0424 |
op_relation |
doi:10.5194/tc-10-1883-2016 https://tc.copernicus.org/articles/10/1883/2016/ |
op_doi |
https://doi.org/10.5194/tc-10-1883-2016 |
container_title |
The Cryosphere |
container_volume |
10 |
container_issue |
4 |
container_start_page |
1883 |
op_container_end_page |
1896 |
_version_ |
1766260334980497408 |