Interaction of marine ice-sheet instabilities in two drainage basins
The initiation of a marine ice-sheet instability (MISI) is generally discussed from the ocean side of the ice sheet. It has been shown that the reduction in ice-shelf buttressing and softening of the coastal ice can destabilize a marine ice sheet if the bedrock is sloping upward towards the ocean. U...
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ftubpotsdam:oai:kobv.de-opus4-uni-potsdam:40890 2024-04-21T08:04:55+00:00 Interaction of marine ice-sheet instabilities in two drainage basins Feldmann, Johannes Levermann, Anders (Prof. Dr.) 2019-01-17 application/pdf https://publishup.uni-potsdam.de/frontdoor/index/index/docId/40890 https://nbn-resolving.org/urn:nbn:de:kobv:517-opus4-408903 https://doi.org/10.25932/publishup-40890 https://publishup.uni-potsdam.de/files/40890/pmnr511.pdf eng eng https://publishup.uni-potsdam.de/frontdoor/index/index/docId/40890 urn:nbn:de:kobv:517-opus4-408903 https://nbn-resolving.org/urn:nbn:de:kobv:517-opus4-408903 https://doi.org/10.25932/publishup-40890 https://publishup.uni-potsdam.de/files/40890/pmnr511.pdf https://creativecommons.org/licenses/by/4.0/ info:eu-repo/semantics/openAccess ddc:910 Mathematisch-Naturwissenschaftliche Fakultät postprint doc-type:article 2019 ftubpotsdam https://doi.org/10.25932/publishup-40890 2024-03-27T15:02:48Z The initiation of a marine ice-sheet instability (MISI) is generally discussed from the ocean side of the ice sheet. It has been shown that the reduction in ice-shelf buttressing and softening of the coastal ice can destabilize a marine ice sheet if the bedrock is sloping upward towards the ocean. Using a conceptional flow-line geometry, we investigate the possibility of whether a MISI can be triggered from the direction of the ice divide as opposed to coastal forcing and explore the interaction between connected basins. We find that the initiation of a MISI in one basin can induce a destabilization in the other. The underlying mechanism of basin interaction is based on dynamic thinning and a consecutive motion of the ice divide which induces a thinning in the adjacent basin and a successive initiation of the instability. Our simplified and symmetric topographic setup allows scaling both the geometry and the transition time between both instabilities. We find that the ice profile follows a universal shape that is scaled with the horizontal extent of the ice sheet and that the same exponent of 1/2 applies for the scaling relation between central surface elevation and horizontal extent as in the pure shallow ice approximation (Vialov profile). Altering the central bed elevation, we find that the extent of grounding-line retreat in one basin determines the degree of interaction with the other. Different scenarios of basin interaction are discussed based on our modeling results as well as on a conceptual flux-balance analysis. We conclude that for the three-dimensional case, the possibility of drainage basin interaction on timescales on the order of 1 kyr or larger cannot be excluded and hence needs further investigation. Article in Journal/Newspaper Ice Sheet Ice Shelf University of Potsdam: publish.UP |
institution |
Open Polar |
collection |
University of Potsdam: publish.UP |
op_collection_id |
ftubpotsdam |
language |
English |
topic |
ddc:910 Mathematisch-Naturwissenschaftliche Fakultät |
spellingShingle |
ddc:910 Mathematisch-Naturwissenschaftliche Fakultät Feldmann, Johannes Levermann, Anders (Prof. Dr.) Interaction of marine ice-sheet instabilities in two drainage basins |
topic_facet |
ddc:910 Mathematisch-Naturwissenschaftliche Fakultät |
description |
The initiation of a marine ice-sheet instability (MISI) is generally discussed from the ocean side of the ice sheet. It has been shown that the reduction in ice-shelf buttressing and softening of the coastal ice can destabilize a marine ice sheet if the bedrock is sloping upward towards the ocean. Using a conceptional flow-line geometry, we investigate the possibility of whether a MISI can be triggered from the direction of the ice divide as opposed to coastal forcing and explore the interaction between connected basins. We find that the initiation of a MISI in one basin can induce a destabilization in the other. The underlying mechanism of basin interaction is based on dynamic thinning and a consecutive motion of the ice divide which induces a thinning in the adjacent basin and a successive initiation of the instability. Our simplified and symmetric topographic setup allows scaling both the geometry and the transition time between both instabilities. We find that the ice profile follows a universal shape that is scaled with the horizontal extent of the ice sheet and that the same exponent of 1/2 applies for the scaling relation between central surface elevation and horizontal extent as in the pure shallow ice approximation (Vialov profile). Altering the central bed elevation, we find that the extent of grounding-line retreat in one basin determines the degree of interaction with the other. Different scenarios of basin interaction are discussed based on our modeling results as well as on a conceptual flux-balance analysis. We conclude that for the three-dimensional case, the possibility of drainage basin interaction on timescales on the order of 1 kyr or larger cannot be excluded and hence needs further investigation. |
format |
Article in Journal/Newspaper |
author |
Feldmann, Johannes Levermann, Anders (Prof. Dr.) |
author_facet |
Feldmann, Johannes Levermann, Anders (Prof. Dr.) |
author_sort |
Feldmann, Johannes |
title |
Interaction of marine ice-sheet instabilities in two drainage basins |
title_short |
Interaction of marine ice-sheet instabilities in two drainage basins |
title_full |
Interaction of marine ice-sheet instabilities in two drainage basins |
title_fullStr |
Interaction of marine ice-sheet instabilities in two drainage basins |
title_full_unstemmed |
Interaction of marine ice-sheet instabilities in two drainage basins |
title_sort |
interaction of marine ice-sheet instabilities in two drainage basins |
publishDate |
2019 |
url |
https://publishup.uni-potsdam.de/frontdoor/index/index/docId/40890 https://nbn-resolving.org/urn:nbn:de:kobv:517-opus4-408903 https://doi.org/10.25932/publishup-40890 https://publishup.uni-potsdam.de/files/40890/pmnr511.pdf |
genre |
Ice Sheet Ice Shelf |
genre_facet |
Ice Sheet Ice Shelf |
op_relation |
https://publishup.uni-potsdam.de/frontdoor/index/index/docId/40890 urn:nbn:de:kobv:517-opus4-408903 https://nbn-resolving.org/urn:nbn:de:kobv:517-opus4-408903 https://doi.org/10.25932/publishup-40890 https://publishup.uni-potsdam.de/files/40890/pmnr511.pdf |
op_rights |
https://creativecommons.org/licenses/by/4.0/ info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.25932/publishup-40890 |
_version_ |
1796944438616915968 |