Stabilizing effect of mélange buttressing on the marine ice-cliff instability of the West Antarctic Ice Sheet
Owing to global warming and particularly high regional ocean warming, both Thwaites and Pine Island Glaciers in the Amundsen region of the Antarctic Ice Sheet could lose their buttressing ice shelves over time. We analyse the possible consequences using the parallel ice sheet model (PISM), applying...
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ftleibnizopen:oai:oai.leibnizopen.de:4e9q6YoBg80Wlv18OnFu 2023-10-29T02:30:56+01:00 Stabilizing effect of mélange buttressing on the marine ice-cliff instability of the West Antarctic Ice Sheet Schlemm, Tanja Feldmann, Johannes Winkelmann, Ricarda Levermann, Anders 2022 application/pdf https://oa.tib.eu/renate/handle/123456789/11865 https://doi.org/10.34657/10898 eng eng Katlenburg-Lindau : Copernicus CC BY 4.0 Unported https://creativecommons.org/licenses/by/4.0 The Cryosphere : TC 16 (2022), Nr. 5 Antarctica Pine Island Glacier Thwaites Glacier West Antarctica global warming 910 article Text 2022 ftleibnizopen https://doi.org/10.34657/10898 2023-10-01T23:11:35Z Owing to global warming and particularly high regional ocean warming, both Thwaites and Pine Island Glaciers in the Amundsen region of the Antarctic Ice Sheet could lose their buttressing ice shelves over time. We analyse the possible consequences using the parallel ice sheet model (PISM), applying a simple cliff-calving parameterization and an ice mélange-buttressing model. We find that the instantaneous loss of ice-shelf buttressing, due to enforced ice-shelf melting, initiates grounding-line retreat and triggers marine ice sheet instability (MISI). As a consequence, the grounding line progresses into the interior of the West Antarctic Ice Sheet and leads to a sea level contribution of 0.6m within 100a. By subjecting the exposed ice cliffs to cliff calving using our simplified parameterization, we also analyse marine ice cliff instability (MICI). In our simulations it can double or even triple the sea level contribution depending on the only loosely constrained parameter that determines the maximum cliff-calving rate. The speed of MICI depends on this upper bound of the calving rate, which is given by the ice mélange buttressing the glacier. However, stabilization of MICI may occur for geometric reasons. Because the embayment geometry changes as MICI advances into the interior of the ice sheet, the upper bound on calving rates is reduced and the progress of MICI is slowed down. Although we cannot claim that our simulations bear relevant quantitative estimates of the effect of ice-mélange buttressing on MICI, the mechanism has the potential to stop the instability. Further research is needed to evaluate its role for the past and future evolution of the Antarctic Ice Sheet. Leibniz_Fonds publishedVersion Article in Journal/Newspaper Antarc* Antarctic Antarctica Ice Sheet Ice Shelf Ice Shelves Pine Island Pine Island Glacier The Cryosphere Thwaites Glacier West Antarctica LeibnizOpen (The Leibniz Association) |
institution |
Open Polar |
collection |
LeibnizOpen (The Leibniz Association) |
op_collection_id |
ftleibnizopen |
language |
English |
topic |
Antarctica Pine Island Glacier Thwaites Glacier West Antarctica global warming 910 |
spellingShingle |
Antarctica Pine Island Glacier Thwaites Glacier West Antarctica global warming 910 Schlemm, Tanja Feldmann, Johannes Winkelmann, Ricarda Levermann, Anders Stabilizing effect of mélange buttressing on the marine ice-cliff instability of the West Antarctic Ice Sheet |
topic_facet |
Antarctica Pine Island Glacier Thwaites Glacier West Antarctica global warming 910 |
description |
Owing to global warming and particularly high regional ocean warming, both Thwaites and Pine Island Glaciers in the Amundsen region of the Antarctic Ice Sheet could lose their buttressing ice shelves over time. We analyse the possible consequences using the parallel ice sheet model (PISM), applying a simple cliff-calving parameterization and an ice mélange-buttressing model. We find that the instantaneous loss of ice-shelf buttressing, due to enforced ice-shelf melting, initiates grounding-line retreat and triggers marine ice sheet instability (MISI). As a consequence, the grounding line progresses into the interior of the West Antarctic Ice Sheet and leads to a sea level contribution of 0.6m within 100a. By subjecting the exposed ice cliffs to cliff calving using our simplified parameterization, we also analyse marine ice cliff instability (MICI). In our simulations it can double or even triple the sea level contribution depending on the only loosely constrained parameter that determines the maximum cliff-calving rate. The speed of MICI depends on this upper bound of the calving rate, which is given by the ice mélange buttressing the glacier. However, stabilization of MICI may occur for geometric reasons. Because the embayment geometry changes as MICI advances into the interior of the ice sheet, the upper bound on calving rates is reduced and the progress of MICI is slowed down. Although we cannot claim that our simulations bear relevant quantitative estimates of the effect of ice-mélange buttressing on MICI, the mechanism has the potential to stop the instability. Further research is needed to evaluate its role for the past and future evolution of the Antarctic Ice Sheet. Leibniz_Fonds publishedVersion |
format |
Article in Journal/Newspaper |
author |
Schlemm, Tanja Feldmann, Johannes Winkelmann, Ricarda Levermann, Anders |
author_facet |
Schlemm, Tanja Feldmann, Johannes Winkelmann, Ricarda Levermann, Anders |
author_sort |
Schlemm, Tanja |
title |
Stabilizing effect of mélange buttressing on the marine ice-cliff instability of the West Antarctic Ice Sheet |
title_short |
Stabilizing effect of mélange buttressing on the marine ice-cliff instability of the West Antarctic Ice Sheet |
title_full |
Stabilizing effect of mélange buttressing on the marine ice-cliff instability of the West Antarctic Ice Sheet |
title_fullStr |
Stabilizing effect of mélange buttressing on the marine ice-cliff instability of the West Antarctic Ice Sheet |
title_full_unstemmed |
Stabilizing effect of mélange buttressing on the marine ice-cliff instability of the West Antarctic Ice Sheet |
title_sort |
stabilizing effect of mélange buttressing on the marine ice-cliff instability of the west antarctic ice sheet |
publisher |
Katlenburg-Lindau : Copernicus |
publishDate |
2022 |
url |
https://oa.tib.eu/renate/handle/123456789/11865 https://doi.org/10.34657/10898 |
genre |
Antarc* Antarctic Antarctica Ice Sheet Ice Shelf Ice Shelves Pine Island Pine Island Glacier The Cryosphere Thwaites Glacier West Antarctica |
genre_facet |
Antarc* Antarctic Antarctica Ice Sheet Ice Shelf Ice Shelves Pine Island Pine Island Glacier The Cryosphere Thwaites Glacier West Antarctica |
op_source |
The Cryosphere : TC 16 (2022), Nr. 5 |
op_rights |
CC BY 4.0 Unported https://creativecommons.org/licenses/by/4.0 |
op_doi |
https://doi.org/10.34657/10898 |
_version_ |
1781063865690226688 |