Hysteresis of idealized marine outlet glaciers under variation of pinning-point buttressing
Ice-shelf pinning points such as ice rises or ice rumples can have an important role in regulating the ice discharge of marine outlet glaciers. For instance, the observed gradual ungrounding of the ice shelf of West Antarctica's Thwaites Glacier from its last pinning points diminishes the buttr...
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ftgfzpotsdam:oai:gfzpublic.gfz-potsdam.de:item_5016107 2023-06-11T04:06:53+02:00 Hysteresis of idealized marine outlet glaciers under variation of pinning-point buttressing Feldmann, J. Winkelmann, R. Levermann, A. 2023 https://gfzpublic.gfz-potsdam.de/pubman/item/item_5016107 eng eng info:eu-repo/semantics/altIdentifier/doi/10.57757/IUGG23-0358 https://gfzpublic.gfz-potsdam.de/pubman/item/item_5016107 XXVIII General Assembly of the International Union of Geodesy and Geophysics (IUGG) info:eu-repo/semantics/conferenceObject 2023 ftgfzpotsdam https://doi.org/10.57757/IUGG23-0358 2023-04-23T23:38:34Z Ice-shelf pinning points such as ice rises or ice rumples can have an important role in regulating the ice discharge of marine outlet glaciers. For instance, the observed gradual ungrounding of the ice shelf of West Antarctica's Thwaites Glacier from its last pinning points diminishes the buttressing effect of the ice shelf and thus contributes to the destabilization of the outlet. Here we use an idealized experimental setting to simulate the response of an Antarctic-type marine outlet glacier to a successive ungrounding of its ice shelf from a pinning point. This is realized by perturbing steady states by a step-wise lowering of the pinning point, which induces a buttressing reduction. After the complete detachment of the ice shelf from the pinning point the perturbation is reversed, i.e., the pinnning point is incrementally elevated toward its initial elevation. First results show that the glacier retreat down the landward down-sloping (retrograde) bed, induced by the loss in buttressing, can be reversible in case of a relatively flat retrograde bed slope. For steeper slopes, glacier retreat and re-advance show a hysteretic behavior. Thus, if the bed depression is sufficiently deep, the glacier does not recover from its fully retreated state even for pinning-point elevations that are higher than the initial elevation. Conference Object Antarc* Antarctic Ice Shelf Thwaites Glacier GFZpublic (German Research Centre for Geosciences, Helmholtz-Zentrum Potsdam) Antarctic Thwaites Glacier ENVELOPE(-106.750,-106.750,-75.500,-75.500) |
institution |
Open Polar |
collection |
GFZpublic (German Research Centre for Geosciences, Helmholtz-Zentrum Potsdam) |
op_collection_id |
ftgfzpotsdam |
language |
English |
description |
Ice-shelf pinning points such as ice rises or ice rumples can have an important role in regulating the ice discharge of marine outlet glaciers. For instance, the observed gradual ungrounding of the ice shelf of West Antarctica's Thwaites Glacier from its last pinning points diminishes the buttressing effect of the ice shelf and thus contributes to the destabilization of the outlet. Here we use an idealized experimental setting to simulate the response of an Antarctic-type marine outlet glacier to a successive ungrounding of its ice shelf from a pinning point. This is realized by perturbing steady states by a step-wise lowering of the pinning point, which induces a buttressing reduction. After the complete detachment of the ice shelf from the pinning point the perturbation is reversed, i.e., the pinnning point is incrementally elevated toward its initial elevation. First results show that the glacier retreat down the landward down-sloping (retrograde) bed, induced by the loss in buttressing, can be reversible in case of a relatively flat retrograde bed slope. For steeper slopes, glacier retreat and re-advance show a hysteretic behavior. Thus, if the bed depression is sufficiently deep, the glacier does not recover from its fully retreated state even for pinning-point elevations that are higher than the initial elevation. |
format |
Conference Object |
author |
Feldmann, J. Winkelmann, R. Levermann, A. |
spellingShingle |
Feldmann, J. Winkelmann, R. Levermann, A. Hysteresis of idealized marine outlet glaciers under variation of pinning-point buttressing |
author_facet |
Feldmann, J. Winkelmann, R. Levermann, A. |
author_sort |
Feldmann, J. |
title |
Hysteresis of idealized marine outlet glaciers under variation of pinning-point buttressing |
title_short |
Hysteresis of idealized marine outlet glaciers under variation of pinning-point buttressing |
title_full |
Hysteresis of idealized marine outlet glaciers under variation of pinning-point buttressing |
title_fullStr |
Hysteresis of idealized marine outlet glaciers under variation of pinning-point buttressing |
title_full_unstemmed |
Hysteresis of idealized marine outlet glaciers under variation of pinning-point buttressing |
title_sort |
hysteresis of idealized marine outlet glaciers under variation of pinning-point buttressing |
publishDate |
2023 |
url |
https://gfzpublic.gfz-potsdam.de/pubman/item/item_5016107 |
long_lat |
ENVELOPE(-106.750,-106.750,-75.500,-75.500) |
geographic |
Antarctic Thwaites Glacier |
geographic_facet |
Antarctic Thwaites Glacier |
genre |
Antarc* Antarctic Ice Shelf Thwaites Glacier |
genre_facet |
Antarc* Antarctic Ice Shelf Thwaites Glacier |
op_source |
XXVIII General Assembly of the International Union of Geodesy and Geophysics (IUGG) |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.57757/IUGG23-0358 https://gfzpublic.gfz-potsdam.de/pubman/item/item_5016107 |
op_doi |
https://doi.org/10.57757/IUGG23-0358 |
_version_ |
1768379091096961024 |