Dynamic influence of pinning points on marine ice-sheet stability: a numerical study in Dronning Maud Land, East Antarctica
The East Antarctic ice sheet is likely more stable than its West Antarctic counterpart because its bed is largely lying above sea level. However, the ice sheet in Dronning Maud Land, East Antarctica, contains marine sectors that are in contact with the ocean through overdeepened marine basins inters...
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Online Access: | http://www.osti.gov/servlets/purl/1375915 https://www.osti.gov/biblio/1375915 https://doi.org/10.5194/tc-10-2623-2016 |
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ftosti:oai:osti.gov:1375915 2023-07-30T03:58:23+02:00 Dynamic influence of pinning points on marine ice-sheet stability: a numerical study in Dronning Maud Land, East Antarctica Favier, Lionel Pattyn, Frank Berger, Sophie Drews, Reinhard 2023-06-26 application/pdf http://www.osti.gov/servlets/purl/1375915 https://www.osti.gov/biblio/1375915 https://doi.org/10.5194/tc-10-2623-2016 unknown http://www.osti.gov/servlets/purl/1375915 https://www.osti.gov/biblio/1375915 https://doi.org/10.5194/tc-10-2623-2016 doi:10.5194/tc-10-2623-2016 58 GEOSCIENCES 2023 ftosti https://doi.org/10.5194/tc-10-2623-2016 2023-07-11T09:20:22Z The East Antarctic ice sheet is likely more stable than its West Antarctic counterpart because its bed is largely lying above sea level. However, the ice sheet in Dronning Maud Land, East Antarctica, contains marine sectors that are in contact with the ocean through overdeepened marine basins interspersed by grounded ice promontories and ice rises, pinning and stabilising the ice shelves. In this paper, we use the ice-sheet model BISICLES to investigate the effect of sub-ice-shelf melting, using a series of scenarios compliant with current values, on the ice-dynamic stability of the outlet glaciers between the Lazarev and Roi Baudouin ice shelves over the next millennium. Overall, the sub-ice-shelf melting substantially impacts the sea-level contribution. Locally, we predict a short-term rapid grounding-line retreat of the overdeepened outlet glacier Hansenbreen, which further induces the transition of the bordering ice promontories into ice rises. Furthermore, our analysis demonstrated that the onset of the marine ice-sheet retreat and subsequent promontory transition into ice rise is controlled by small pinning points, mostly uncharted in pan-Antarctic datasets. Pinning points have a twofold impact on marine ice sheets. They decrease the ice discharge by buttressing effect, and they play a crucial role in initialising marine ice sheets through data assimilation, leading to errors in ice-shelf rheology when omitted. Our results show that unpinning increases the sea-level rise by 10%, while omitting the same pinning point in data assimilation decreases it by 10%, but the more striking effect is in the promontory transition time, advanced by two centuries for unpinning and delayed by almost half a millennium when the pinning point is missing in data assimilation. As a result, pinning points exert a subtle influence on ice dynamics at the kilometre scale, which calls for a better knowledge of the Antarctic margins. Other/Unknown Material Antarc* Antarctic Antarctica Dronning Maud Land East Antarctica Ice Sheet Ice Shelf Ice Shelves SciTec Connect (Office of Scientific and Technical Information - OSTI, U.S. Department of Energy) Antarctic The Antarctic East Antarctica Dronning Maud Land East Antarctic Ice Sheet Lazarev ENVELOPE(12.917,12.917,-69.967,-69.967) Roi Baudouin ENVELOPE(24.461,24.461,-70.438,-70.438) Hansenbreen ENVELOPE(22.750,22.750,-72.100,-72.100) The Cryosphere 10 6 2623 2635 |
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SciTec Connect (Office of Scientific and Technical Information - OSTI, U.S. Department of Energy) |
op_collection_id |
ftosti |
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58 GEOSCIENCES |
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58 GEOSCIENCES Favier, Lionel Pattyn, Frank Berger, Sophie Drews, Reinhard Dynamic influence of pinning points on marine ice-sheet stability: a numerical study in Dronning Maud Land, East Antarctica |
topic_facet |
58 GEOSCIENCES |
description |
The East Antarctic ice sheet is likely more stable than its West Antarctic counterpart because its bed is largely lying above sea level. However, the ice sheet in Dronning Maud Land, East Antarctica, contains marine sectors that are in contact with the ocean through overdeepened marine basins interspersed by grounded ice promontories and ice rises, pinning and stabilising the ice shelves. In this paper, we use the ice-sheet model BISICLES to investigate the effect of sub-ice-shelf melting, using a series of scenarios compliant with current values, on the ice-dynamic stability of the outlet glaciers between the Lazarev and Roi Baudouin ice shelves over the next millennium. Overall, the sub-ice-shelf melting substantially impacts the sea-level contribution. Locally, we predict a short-term rapid grounding-line retreat of the overdeepened outlet glacier Hansenbreen, which further induces the transition of the bordering ice promontories into ice rises. Furthermore, our analysis demonstrated that the onset of the marine ice-sheet retreat and subsequent promontory transition into ice rise is controlled by small pinning points, mostly uncharted in pan-Antarctic datasets. Pinning points have a twofold impact on marine ice sheets. They decrease the ice discharge by buttressing effect, and they play a crucial role in initialising marine ice sheets through data assimilation, leading to errors in ice-shelf rheology when omitted. Our results show that unpinning increases the sea-level rise by 10%, while omitting the same pinning point in data assimilation decreases it by 10%, but the more striking effect is in the promontory transition time, advanced by two centuries for unpinning and delayed by almost half a millennium when the pinning point is missing in data assimilation. As a result, pinning points exert a subtle influence on ice dynamics at the kilometre scale, which calls for a better knowledge of the Antarctic margins. |
author |
Favier, Lionel Pattyn, Frank Berger, Sophie Drews, Reinhard |
author_facet |
Favier, Lionel Pattyn, Frank Berger, Sophie Drews, Reinhard |
author_sort |
Favier, Lionel |
title |
Dynamic influence of pinning points on marine ice-sheet stability: a numerical study in Dronning Maud Land, East Antarctica |
title_short |
Dynamic influence of pinning points on marine ice-sheet stability: a numerical study in Dronning Maud Land, East Antarctica |
title_full |
Dynamic influence of pinning points on marine ice-sheet stability: a numerical study in Dronning Maud Land, East Antarctica |
title_fullStr |
Dynamic influence of pinning points on marine ice-sheet stability: a numerical study in Dronning Maud Land, East Antarctica |
title_full_unstemmed |
Dynamic influence of pinning points on marine ice-sheet stability: a numerical study in Dronning Maud Land, East Antarctica |
title_sort |
dynamic influence of pinning points on marine ice-sheet stability: a numerical study in dronning maud land, east antarctica |
publishDate |
2023 |
url |
http://www.osti.gov/servlets/purl/1375915 https://www.osti.gov/biblio/1375915 https://doi.org/10.5194/tc-10-2623-2016 |
long_lat |
ENVELOPE(12.917,12.917,-69.967,-69.967) ENVELOPE(24.461,24.461,-70.438,-70.438) ENVELOPE(22.750,22.750,-72.100,-72.100) |
geographic |
Antarctic The Antarctic East Antarctica Dronning Maud Land East Antarctic Ice Sheet Lazarev Roi Baudouin Hansenbreen |
geographic_facet |
Antarctic The Antarctic East Antarctica Dronning Maud Land East Antarctic Ice Sheet Lazarev Roi Baudouin Hansenbreen |
genre |
Antarc* Antarctic Antarctica Dronning Maud Land East Antarctica Ice Sheet Ice Shelf Ice Shelves |
genre_facet |
Antarc* Antarctic Antarctica Dronning Maud Land East Antarctica Ice Sheet Ice Shelf Ice Shelves |
op_relation |
http://www.osti.gov/servlets/purl/1375915 https://www.osti.gov/biblio/1375915 https://doi.org/10.5194/tc-10-2623-2016 doi:10.5194/tc-10-2623-2016 |
op_doi |
https://doi.org/10.5194/tc-10-2623-2016 |
container_title |
The Cryosphere |
container_volume |
10 |
container_issue |
6 |
container_start_page |
2623 |
op_container_end_page |
2635 |
_version_ |
1772821194735616000 |