Geometric controls of tidewater glacier dynamics
Retreat of marine outlet glaciers often initiates depletion of inland ice through dynamic adjustments of the upstream glacier. The local topography of a fjord may promote or inhibit such retreat, and therefore fjord geometry constitutes a critical control on ice sheet mass balance. To quantify the p...
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ftcopernicus:oai:publications.copernicus.org:tc93321 2023-05-15T16:40:36+02:00 Geometric controls of tidewater glacier dynamics Frank, Thomas Åkesson, Henning Fleurian, Basile Morlighem, Mathieu Nisancioglu, Kerim H. 2022-02-17 application/pdf https://doi.org/10.5194/tc-16-581-2022 https://tc.copernicus.org/articles/16/581/2022/ eng eng doi:10.5194/tc-16-581-2022 https://tc.copernicus.org/articles/16/581/2022/ eISSN: 1994-0424 Text 2022 ftcopernicus https://doi.org/10.5194/tc-16-581-2022 2022-02-21T17:22:15Z Retreat of marine outlet glaciers often initiates depletion of inland ice through dynamic adjustments of the upstream glacier. The local topography of a fjord may promote or inhibit such retreat, and therefore fjord geometry constitutes a critical control on ice sheet mass balance. To quantify the processes of ice–topography interactions and enhance the understanding of the dynamics involved, we analyze a multitude of topographic fjord settings and scenarios using the Ice-sheet and Sea-level System Model (ISSM). We systematically study glacier retreat through a variety of artificial fjord geometries and quantify the modeled dynamics directly in relation to topographic features. We find that retreat in an upstream-widening or upstream-deepening fjord does not necessarily promote retreat, as suggested by previous studies. Conversely, it may stabilize a glacier because converging ice flow towards a constriction enhances lateral and basal shear stress gradients. An upstream-narrowing or upstream-shoaling fjord, in turn, may promote retreat since fjord walls or bed provide little stability to the glacier where ice flow diverges. Furthermore, we identify distinct quantitative relationships directly linking grounding line discharge and retreat rate to fjord topography and transfer these results to a long-term study of the retreat of Jakobshavn Isbræ. These findings offer new perspectives on ice–topography interactions and give guidance to an ad hoc assessment of future topographically induced ice loss based on knowledge of the upstream fjord geometry. Text Ice Sheet Jakobshavn Jakobshavn isbræ Tidewater Copernicus Publications: E-Journals Jakobshavn Isbræ ENVELOPE(-49.917,-49.917,69.167,69.167) The Cryosphere 16 2 581 601 |
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Open Polar |
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Copernicus Publications: E-Journals |
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ftcopernicus |
language |
English |
description |
Retreat of marine outlet glaciers often initiates depletion of inland ice through dynamic adjustments of the upstream glacier. The local topography of a fjord may promote or inhibit such retreat, and therefore fjord geometry constitutes a critical control on ice sheet mass balance. To quantify the processes of ice–topography interactions and enhance the understanding of the dynamics involved, we analyze a multitude of topographic fjord settings and scenarios using the Ice-sheet and Sea-level System Model (ISSM). We systematically study glacier retreat through a variety of artificial fjord geometries and quantify the modeled dynamics directly in relation to topographic features. We find that retreat in an upstream-widening or upstream-deepening fjord does not necessarily promote retreat, as suggested by previous studies. Conversely, it may stabilize a glacier because converging ice flow towards a constriction enhances lateral and basal shear stress gradients. An upstream-narrowing or upstream-shoaling fjord, in turn, may promote retreat since fjord walls or bed provide little stability to the glacier where ice flow diverges. Furthermore, we identify distinct quantitative relationships directly linking grounding line discharge and retreat rate to fjord topography and transfer these results to a long-term study of the retreat of Jakobshavn Isbræ. These findings offer new perspectives on ice–topography interactions and give guidance to an ad hoc assessment of future topographically induced ice loss based on knowledge of the upstream fjord geometry. |
format |
Text |
author |
Frank, Thomas Åkesson, Henning Fleurian, Basile Morlighem, Mathieu Nisancioglu, Kerim H. |
spellingShingle |
Frank, Thomas Åkesson, Henning Fleurian, Basile Morlighem, Mathieu Nisancioglu, Kerim H. Geometric controls of tidewater glacier dynamics |
author_facet |
Frank, Thomas Åkesson, Henning Fleurian, Basile Morlighem, Mathieu Nisancioglu, Kerim H. |
author_sort |
Frank, Thomas |
title |
Geometric controls of tidewater glacier dynamics |
title_short |
Geometric controls of tidewater glacier dynamics |
title_full |
Geometric controls of tidewater glacier dynamics |
title_fullStr |
Geometric controls of tidewater glacier dynamics |
title_full_unstemmed |
Geometric controls of tidewater glacier dynamics |
title_sort |
geometric controls of tidewater glacier dynamics |
publishDate |
2022 |
url |
https://doi.org/10.5194/tc-16-581-2022 https://tc.copernicus.org/articles/16/581/2022/ |
long_lat |
ENVELOPE(-49.917,-49.917,69.167,69.167) |
geographic |
Jakobshavn Isbræ |
geographic_facet |
Jakobshavn Isbræ |
genre |
Ice Sheet Jakobshavn Jakobshavn isbræ Tidewater |
genre_facet |
Ice Sheet Jakobshavn Jakobshavn isbræ Tidewater |
op_source |
eISSN: 1994-0424 |
op_relation |
doi:10.5194/tc-16-581-2022 https://tc.copernicus.org/articles/16/581/2022/ |
op_doi |
https://doi.org/10.5194/tc-16-581-2022 |
container_title |
The Cryosphere |
container_volume |
16 |
container_issue |
2 |
container_start_page |
581 |
op_container_end_page |
601 |
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1766031012446339072 |