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...
Main Authors: | , , , |
---|---|
Format: | Article in Journal/Newspaper |
Language: | French |
Published: |
2016
|
Subjects: | |
Online Access: | http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/239626 https://dipot.ulb.ac.be/dspace/bitstream/2013/239626/4/doi_223253.pdf https://dipot.ulb.ac.be/dspace/bitstream/2013/239626/3/tc-10-2623-2016.pdf |
id |
ftunivbruxelles:oai:dipot.ulb.ac.be:2013/239626 |
---|---|
record_format |
openpolar |
spelling |
ftunivbruxelles:oai:dipot.ulb.ac.be:2013/239626 2023-05-15T13:37:30+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 2016-11-09 2 full-text file(s): application/pdf | application/pdf http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/239626 https://dipot.ulb.ac.be/dspace/bitstream/2013/239626/4/doi_223253.pdf https://dipot.ulb.ac.be/dspace/bitstream/2013/239626/3/tc-10-2623-2016.pdf fr fre uri/info:doi/10.5194/tc-10-2623-2016 uri/info:scp/84995466783 https://dipot.ulb.ac.be/dspace/bitstream/2013/239626/4/doi_223253.pdf https://dipot.ulb.ac.be/dspace/bitstream/2013/239626/3/tc-10-2623-2016.pdf http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/239626 2 full-text file(s): info:eu-repo/semantics/openAccess | info:eu-repo/semantics/restrictedAccess The Cryosphere, 10 (6 Glaciologie info:eu-repo/semantics/article info:ulb-repo/semantics/articlePeerReview info:ulb-repo/semantics/openurl/article 2016 ftunivbruxelles 2022-06-12T22:09:21Z 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 10ĝ€%, while omitting the same pinning point in data assimilation decreases it by 10ĝ€ %, 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. Pinning points exert a subtle influence on ice dynamics at the kilometre scale, which calls for a better knowledge of the Antarctic margins. SCOPUS: ar.j info:eu-repo/semantics/published Article in Journal/Newspaper Antarc* Antarctic Antarctica Dronning Maud Land East Antarctica Ice Sheet Ice Shelf Ice Shelves The Cryosphere DI-fusion : dépôt institutionnel de l'Université libre de Bruxelles (ULB) Antarctic Dronning Maud Land East Antarctic Ice Sheet East Antarctica Hansenbreen ENVELOPE(22.750,22.750,-72.100,-72.100) Lazarev ENVELOPE(12.917,12.917,-69.967,-69.967) Roi Baudouin ENVELOPE(24.461,24.461,-70.438,-70.438) The Antarctic |
institution |
Open Polar |
collection |
DI-fusion : dépôt institutionnel de l'Université libre de Bruxelles (ULB) |
op_collection_id |
ftunivbruxelles |
language |
French |
topic |
Glaciologie |
spellingShingle |
Glaciologie 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 |
Glaciologie |
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 10ĝ€%, while omitting the same pinning point in data assimilation decreases it by 10ĝ€ %, 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. Pinning points exert a subtle influence on ice dynamics at the kilometre scale, which calls for a better knowledge of the Antarctic margins. SCOPUS: ar.j info:eu-repo/semantics/published |
format |
Article in Journal/Newspaper |
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 |
2016 |
url |
http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/239626 https://dipot.ulb.ac.be/dspace/bitstream/2013/239626/4/doi_223253.pdf https://dipot.ulb.ac.be/dspace/bitstream/2013/239626/3/tc-10-2623-2016.pdf |
long_lat |
ENVELOPE(22.750,22.750,-72.100,-72.100) ENVELOPE(12.917,12.917,-69.967,-69.967) ENVELOPE(24.461,24.461,-70.438,-70.438) |
geographic |
Antarctic Dronning Maud Land East Antarctic Ice Sheet East Antarctica Hansenbreen Lazarev Roi Baudouin The Antarctic |
geographic_facet |
Antarctic Dronning Maud Land East Antarctic Ice Sheet East Antarctica Hansenbreen Lazarev Roi Baudouin The Antarctic |
genre |
Antarc* Antarctic Antarctica Dronning Maud Land East Antarctica Ice Sheet Ice Shelf Ice Shelves The Cryosphere |
genre_facet |
Antarc* Antarctic Antarctica Dronning Maud Land East Antarctica Ice Sheet Ice Shelf Ice Shelves The Cryosphere |
op_source |
The Cryosphere, 10 (6 |
op_relation |
uri/info:doi/10.5194/tc-10-2623-2016 uri/info:scp/84995466783 https://dipot.ulb.ac.be/dspace/bitstream/2013/239626/4/doi_223253.pdf https://dipot.ulb.ac.be/dspace/bitstream/2013/239626/3/tc-10-2623-2016.pdf http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/239626 |
op_rights |
2 full-text file(s): info:eu-repo/semantics/openAccess | info:eu-repo/semantics/restrictedAccess |
_version_ |
1766092571210153984 |