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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ftdoajarticles:oai:doaj.org/article:8e84665dc16646e4a9cf7104318c0fbd 2023-05-15T13:37:55+02:00 Persistence and variability of ice-stream grounding lines on retrograde bed slopes A. A. Robel C. Schoof E. Tziperman 2016-08-01T00:00:00Z https://doi.org/10.5194/tc-10-1883-2016 https://doaj.org/article/8e84665dc16646e4a9cf7104318c0fbd EN eng Copernicus Publications http://www.the-cryosphere.net/10/1883/2016/tc-10-1883-2016.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 1994-0416 1994-0424 doi:10.5194/tc-10-1883-2016 https://doaj.org/article/8e84665dc16646e4a9cf7104318c0fbd The Cryosphere, Vol 10, Iss 4, Pp 1883-1896 (2016) Environmental sciences GE1-350 Geology QE1-996.5 article 2016 ftdoajarticles https://doi.org/10.5194/tc-10-1883-2016 2023-01-08T01:37:18Z 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. Article in Journal/Newspaper Antarc* Antarctica Ice Sheet The Cryosphere West Antarctica Directory of Open Access Journals: DOAJ Articles West Antarctica The Cryosphere 10 4 1883 1896 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Environmental sciences GE1-350 Geology QE1-996.5 |
spellingShingle |
Environmental sciences GE1-350 Geology QE1-996.5 A. A. Robel C. Schoof E. Tziperman Persistence and variability of ice-stream grounding lines on retrograde bed slopes |
topic_facet |
Environmental sciences GE1-350 Geology QE1-996.5 |
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 |
Article in Journal/Newspaper |
author |
A. A. Robel C. Schoof E. Tziperman |
author_facet |
A. A. Robel C. Schoof E. Tziperman |
author_sort |
A. A. Robel |
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 |
publisher |
Copernicus Publications |
publishDate |
2016 |
url |
https://doi.org/10.5194/tc-10-1883-2016 https://doaj.org/article/8e84665dc16646e4a9cf7104318c0fbd |
geographic |
West Antarctica |
geographic_facet |
West Antarctica |
genre |
Antarc* Antarctica Ice Sheet The Cryosphere West Antarctica |
genre_facet |
Antarc* Antarctica Ice Sheet The Cryosphere West Antarctica |
op_source |
The Cryosphere, Vol 10, Iss 4, Pp 1883-1896 (2016) |
op_relation |
http://www.the-cryosphere.net/10/1883/2016/tc-10-1883-2016.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 1994-0416 1994-0424 doi:10.5194/tc-10-1883-2016 https://doaj.org/article/8e84665dc16646e4a9cf7104318c0fbd |
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_ |
1766099457188823040 |