A steady-state model reconstruction of the patagonian ice sheet during the last glacial maximum
During the Last Glacial Maximum (LGM), the Patagonian Ice Sheet (PIS) was the largest Quaternary ice mass in the Southern Hemisphere outside of Antarctica. Although the margins of the LGM ice sheet are now well established through end-moraine mapping and dating, apart from a few modelling and empiri...
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ftdoajarticles:oai:doaj.org/article:878ea0ef37504a6d9e9fb0ab52295fb5 2023-11-12T04:04:11+01:00 A steady-state model reconstruction of the patagonian ice sheet during the last glacial maximum Ingo W. Wolff Neil F. Glasser Stephan Harrison Joanne Laura Wood Alun Hubbard 2023-10-01T00:00:00Z https://doi.org/10.1016/j.qsa.2023.100103 https://doaj.org/article/878ea0ef37504a6d9e9fb0ab52295fb5 EN eng Elsevier http://www.sciencedirect.com/science/article/pii/S2666033423000357 https://doaj.org/toc/2666-0334 2666-0334 doi:10.1016/j.qsa.2023.100103 https://doaj.org/article/878ea0ef37504a6d9e9fb0ab52295fb5 Quaternary Science Advances, Vol 12, Iss , Pp 100103- (2023) Geography. Anthropology. Recreation G Archaeology CC1-960 article 2023 ftdoajarticles https://doi.org/10.1016/j.qsa.2023.100103 2023-10-15T00:35:53Z During the Last Glacial Maximum (LGM), the Patagonian Ice Sheet (PIS) was the largest Quaternary ice mass in the Southern Hemisphere outside of Antarctica. Although the margins of the LGM ice sheet are now well established through end-moraine mapping and dating, apart from a few modelling and empirical studies, there remains a lack of constraint on its thickness and three-dimensional configuration. Here, we provide a high-resolution steady-state model reconstruction of the PIS at its maximum - LGM - extent applied using Nye's perfect-plastic ice rheology. The yield-strength parameter for the perfect-plastic flow model was calibrated against independent empirical reconstructions of the Lago Pueyrredón Glacier, where the former vertical extent of this major outlet glacier is well constrained by cosmogenically-dated trimlines and lateral and end-moraine limits. Using this derived yield-strength parameter, the perfect-plastic model is then applied to multiple flowlines demarking each outlet across the entirety of the PIS in a GIS framework. Our results reveal that the area of the PIS was ∼504,500 km2 (±8.5%) with a corresponding modelled ice volume of ∼554,500 km3 (±10%), equivalent to ∼1.38 m (±10%) of eustatic sea-level lowering at the LGM. Maximum surface elevation was at least 3500m asl although the majority of the ice sheet surface was below 2500 m asl. We find that our ice sheet reconstruction is in good general agreement with previous estimates of net PIS volume derived from transient modelling studies. We attribute the slightly lower aspect-ratio of our ice sheet (and its concomitant 5% reduction in volume and sea-level equivalent) to the lower yield strength applied, based on more temperate and dynamic ice sheet conditions. Article in Journal/Newspaper Antarc* Antarctica Ice Sheet Directory of Open Access Journals: DOAJ Articles Quaternary Science Advances 12 100103 |
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Open Polar |
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Directory of Open Access Journals: DOAJ Articles |
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ftdoajarticles |
language |
English |
topic |
Geography. Anthropology. Recreation G Archaeology CC1-960 |
spellingShingle |
Geography. Anthropology. Recreation G Archaeology CC1-960 Ingo W. Wolff Neil F. Glasser Stephan Harrison Joanne Laura Wood Alun Hubbard A steady-state model reconstruction of the patagonian ice sheet during the last glacial maximum |
topic_facet |
Geography. Anthropology. Recreation G Archaeology CC1-960 |
description |
During the Last Glacial Maximum (LGM), the Patagonian Ice Sheet (PIS) was the largest Quaternary ice mass in the Southern Hemisphere outside of Antarctica. Although the margins of the LGM ice sheet are now well established through end-moraine mapping and dating, apart from a few modelling and empirical studies, there remains a lack of constraint on its thickness and three-dimensional configuration. Here, we provide a high-resolution steady-state model reconstruction of the PIS at its maximum - LGM - extent applied using Nye's perfect-plastic ice rheology. The yield-strength parameter for the perfect-plastic flow model was calibrated against independent empirical reconstructions of the Lago Pueyrredón Glacier, where the former vertical extent of this major outlet glacier is well constrained by cosmogenically-dated trimlines and lateral and end-moraine limits. Using this derived yield-strength parameter, the perfect-plastic model is then applied to multiple flowlines demarking each outlet across the entirety of the PIS in a GIS framework. Our results reveal that the area of the PIS was ∼504,500 km2 (±8.5%) with a corresponding modelled ice volume of ∼554,500 km3 (±10%), equivalent to ∼1.38 m (±10%) of eustatic sea-level lowering at the LGM. Maximum surface elevation was at least 3500m asl although the majority of the ice sheet surface was below 2500 m asl. We find that our ice sheet reconstruction is in good general agreement with previous estimates of net PIS volume derived from transient modelling studies. We attribute the slightly lower aspect-ratio of our ice sheet (and its concomitant 5% reduction in volume and sea-level equivalent) to the lower yield strength applied, based on more temperate and dynamic ice sheet conditions. |
format |
Article in Journal/Newspaper |
author |
Ingo W. Wolff Neil F. Glasser Stephan Harrison Joanne Laura Wood Alun Hubbard |
author_facet |
Ingo W. Wolff Neil F. Glasser Stephan Harrison Joanne Laura Wood Alun Hubbard |
author_sort |
Ingo W. Wolff |
title |
A steady-state model reconstruction of the patagonian ice sheet during the last glacial maximum |
title_short |
A steady-state model reconstruction of the patagonian ice sheet during the last glacial maximum |
title_full |
A steady-state model reconstruction of the patagonian ice sheet during the last glacial maximum |
title_fullStr |
A steady-state model reconstruction of the patagonian ice sheet during the last glacial maximum |
title_full_unstemmed |
A steady-state model reconstruction of the patagonian ice sheet during the last glacial maximum |
title_sort |
steady-state model reconstruction of the patagonian ice sheet during the last glacial maximum |
publisher |
Elsevier |
publishDate |
2023 |
url |
https://doi.org/10.1016/j.qsa.2023.100103 https://doaj.org/article/878ea0ef37504a6d9e9fb0ab52295fb5 |
genre |
Antarc* Antarctica Ice Sheet |
genre_facet |
Antarc* Antarctica Ice Sheet |
op_source |
Quaternary Science Advances, Vol 12, Iss , Pp 100103- (2023) |
op_relation |
http://www.sciencedirect.com/science/article/pii/S2666033423000357 https://doaj.org/toc/2666-0334 2666-0334 doi:10.1016/j.qsa.2023.100103 https://doaj.org/article/878ea0ef37504a6d9e9fb0ab52295fb5 |
op_doi |
https://doi.org/10.1016/j.qsa.2023.100103 |
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Quaternary Science Advances |
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100103 |
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