A continuum model (PSUMEL1) of ice mélange and its role during retreat of the Antarctic Ice Sheet
Rapidly retreating thick ice fronts can generate large amounts of mélange (floating ice debris), which may affect episodes of rapid retreat of Antarctic marine ice. In modern Greenland fjords, mélange provides substantial back pressure on calving ice faces, which slows ice front calving rates. On th...
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ftdoajarticles:oai:doaj.org/article:7844d33705f1413b9d86eae1d61dd05d 2023-05-15T13:45:20+02:00 A continuum model (PSUMEL1) of ice mélange and its role during retreat of the Antarctic Ice Sheet D. Pollard R. M. DeConto R. B. Alley 2018-12-01T00:00:00Z https://doi.org/10.5194/gmd-11-5149-2018 https://doaj.org/article/7844d33705f1413b9d86eae1d61dd05d EN eng Copernicus Publications https://www.geosci-model-dev.net/11/5149/2018/gmd-11-5149-2018.pdf https://doaj.org/toc/1991-959X https://doaj.org/toc/1991-9603 doi:10.5194/gmd-11-5149-2018 1991-959X 1991-9603 https://doaj.org/article/7844d33705f1413b9d86eae1d61dd05d Geoscientific Model Development, Vol 11, Pp 5149-5172 (2018) Geology QE1-996.5 article 2018 ftdoajarticles https://doi.org/10.5194/gmd-11-5149-2018 2022-12-31T06:05:56Z Rapidly retreating thick ice fronts can generate large amounts of mélange (floating ice debris), which may affect episodes of rapid retreat of Antarctic marine ice. In modern Greenland fjords, mélange provides substantial back pressure on calving ice faces, which slows ice front calving rates. On the much larger scales of West Antarctica, it is unknown if mélange could clog seaways and provide enough back pressure to act as a negative feedback slowing retreat. Here we describe a new mélange model, using a continuum-mechanical formulation that is computationally feasible for long-term continental Antarctic applications. It is tested in an idealized rectangular channel and calibrated very basically using observed modern conditions in Jakobshavn fjord, West Greenland. The model is then applied to drastic retreat of Antarctic ice in response to warm mid-Pliocene climate. With mélange parameter values that yield reasonable modern Jakobshavn results, Antarctic marine ice still retreats drastically in the Pliocene simulations, with little slowdown despite the huge amounts of mélange generated. This holds both for the rapid early collapse of West Antarctica and for later retreat into major East Antarctic basins. If parameter values are changed to make the mélange much more resistive to flow, far outside the range for reasonable Jakobshavn results, West Antarctica still collapses and retreat is slowed or prevented only in a few East Antarctic basins. Article in Journal/Newspaper Antarc* Antarctic Antarctica Greenland Ice Sheet Jakobshavn West Antarctica Directory of Open Access Journals: DOAJ Articles Antarctic The Antarctic West Antarctica Greenland Geoscientific Model Development 11 12 5149 5172 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Geology QE1-996.5 |
spellingShingle |
Geology QE1-996.5 D. Pollard R. M. DeConto R. B. Alley A continuum model (PSUMEL1) of ice mélange and its role during retreat of the Antarctic Ice Sheet |
topic_facet |
Geology QE1-996.5 |
description |
Rapidly retreating thick ice fronts can generate large amounts of mélange (floating ice debris), which may affect episodes of rapid retreat of Antarctic marine ice. In modern Greenland fjords, mélange provides substantial back pressure on calving ice faces, which slows ice front calving rates. On the much larger scales of West Antarctica, it is unknown if mélange could clog seaways and provide enough back pressure to act as a negative feedback slowing retreat. Here we describe a new mélange model, using a continuum-mechanical formulation that is computationally feasible for long-term continental Antarctic applications. It is tested in an idealized rectangular channel and calibrated very basically using observed modern conditions in Jakobshavn fjord, West Greenland. The model is then applied to drastic retreat of Antarctic ice in response to warm mid-Pliocene climate. With mélange parameter values that yield reasonable modern Jakobshavn results, Antarctic marine ice still retreats drastically in the Pliocene simulations, with little slowdown despite the huge amounts of mélange generated. This holds both for the rapid early collapse of West Antarctica and for later retreat into major East Antarctic basins. If parameter values are changed to make the mélange much more resistive to flow, far outside the range for reasonable Jakobshavn results, West Antarctica still collapses and retreat is slowed or prevented only in a few East Antarctic basins. |
format |
Article in Journal/Newspaper |
author |
D. Pollard R. M. DeConto R. B. Alley |
author_facet |
D. Pollard R. M. DeConto R. B. Alley |
author_sort |
D. Pollard |
title |
A continuum model (PSUMEL1) of ice mélange and its role during retreat of the Antarctic Ice Sheet |
title_short |
A continuum model (PSUMEL1) of ice mélange and its role during retreat of the Antarctic Ice Sheet |
title_full |
A continuum model (PSUMEL1) of ice mélange and its role during retreat of the Antarctic Ice Sheet |
title_fullStr |
A continuum model (PSUMEL1) of ice mélange and its role during retreat of the Antarctic Ice Sheet |
title_full_unstemmed |
A continuum model (PSUMEL1) of ice mélange and its role during retreat of the Antarctic Ice Sheet |
title_sort |
continuum model (psumel1) of ice mélange and its role during retreat of the antarctic ice sheet |
publisher |
Copernicus Publications |
publishDate |
2018 |
url |
https://doi.org/10.5194/gmd-11-5149-2018 https://doaj.org/article/7844d33705f1413b9d86eae1d61dd05d |
geographic |
Antarctic The Antarctic West Antarctica Greenland |
geographic_facet |
Antarctic The Antarctic West Antarctica Greenland |
genre |
Antarc* Antarctic Antarctica Greenland Ice Sheet Jakobshavn West Antarctica |
genre_facet |
Antarc* Antarctic Antarctica Greenland Ice Sheet Jakobshavn West Antarctica |
op_source |
Geoscientific Model Development, Vol 11, Pp 5149-5172 (2018) |
op_relation |
https://www.geosci-model-dev.net/11/5149/2018/gmd-11-5149-2018.pdf https://doaj.org/toc/1991-959X https://doaj.org/toc/1991-9603 doi:10.5194/gmd-11-5149-2018 1991-959X 1991-9603 https://doaj.org/article/7844d33705f1413b9d86eae1d61dd05d |
op_doi |
https://doi.org/10.5194/gmd-11-5149-2018 |
container_title |
Geoscientific Model Development |
container_volume |
11 |
container_issue |
12 |
container_start_page |
5149 |
op_container_end_page |
5172 |
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