Simulating the Laurentide Ice Sheet of the Last Glacial Maximum
<p>In the last decades, great effort has been made to reconstruct the Laurentide Ice Sheet (LIS) during the Last Glacial Maximum (LGM; ca. 21 000 years before present, 21 kyr ago). Uncertainties underlying its modelling have led to notable differences in fundamental features such as its maximu...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2023-05-01
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| Series: | The Cryosphere |
| Online Access: | https://tc.copernicus.org/articles/17/2139/2023/tc-17-2139-2023.pdf |
| _version_ | 1797820336632233984 |
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| author | D. Moreno-Parada D. Moreno-Parada J. Alvarez-Solas J. Alvarez-Solas J. Blasco J. Blasco J. Blasco M. Montoya M. Montoya A. Robinson A. Robinson A. Robinson |
| author_facet | D. Moreno-Parada D. Moreno-Parada J. Alvarez-Solas J. Alvarez-Solas J. Blasco J. Blasco J. Blasco M. Montoya M. Montoya A. Robinson A. Robinson A. Robinson |
| author_sort | D. Moreno-Parada |
| collection | DOAJ |
| description | <p>In the last decades, great effort has been made to reconstruct the Laurentide Ice Sheet (LIS) during the Last Glacial Maximum (LGM; ca. 21 000 years before present, 21 kyr ago). Uncertainties underlying its modelling have led to notable differences in fundamental features such as its maximum elevation, extent and total volume. As a result, the uncertainty in ice dynamics and thus in ice extent, volume and ice stream stability remains large. We herein use a higher-order three-dimensional ice sheet model to simulate the LIS under LGM boundary conditions for a number of basal friction formulations of varying complexity. Their consequences for the Laurentide ice streams, configuration, extent and volume are explicitly quantified. Total volume and ice extent generally reach a constant equilibrium value that falls close to prior LIS reconstructions. Simulations exhibit high sensitivity to the dependency of the basal shear stress on the sliding velocity. In particular, a regularised Coulomb friction formulation appears to be the best choice in terms of ice volume and ice stream realism. Pronounced differences are found when the basal friction stress is thermomechanically coupled: the base remains colder, and the LIS volume is lower than in the purely mechanical friction scenario counterpart. Thermomechanical coupling is fundamental for producing rapid ice streaming, yet it leads to a similar ice distribution overall.</p> |
| first_indexed | 2024-03-13T09:37:55Z |
| format | Article |
| id | doaj.art-ecef6e7b7d43411da33c1b82175bd511 |
| institution | Directory Open Access Journal |
| issn | 1994-0416 1994-0424 |
| language | English |
| last_indexed | 2024-03-13T09:37:55Z |
| publishDate | 2023-05-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | The Cryosphere |
| spelling | doaj.art-ecef6e7b7d43411da33c1b82175bd5112023-05-25T11:13:18ZengCopernicus PublicationsThe Cryosphere1994-04161994-04242023-05-01172139215610.5194/tc-17-2139-2023Simulating the Laurentide Ice Sheet of the Last Glacial MaximumD. Moreno-Parada0D. Moreno-Parada1J. Alvarez-Solas2J. Alvarez-Solas3J. Blasco4J. Blasco5J. Blasco6M. Montoya7M. Montoya8A. Robinson9A. Robinson10A. Robinson11Departamento de Física de la Tierra y Astrofísica, Universidad Complutense de Madrid, Facultad de Ciencias Físicas, 28040 Madrid, SpainInstituto de Geociencias, Consejo Superior de Investigaciones Científicas, Universidad Complutense de Madrid, 28040 Madrid, SpainDepartamento de Física de la Tierra y Astrofísica, Universidad Complutense de Madrid, Facultad de Ciencias Físicas, 28040 Madrid, SpainInstituto de Geociencias, Consejo Superior de Investigaciones Científicas, Universidad Complutense de Madrid, 28040 Madrid, SpainDepartamento de Física de la Tierra y Astrofísica, Universidad Complutense de Madrid, Facultad de Ciencias Físicas, 28040 Madrid, SpainInstituto de Geociencias, Consejo Superior de Investigaciones Científicas, Universidad Complutense de Madrid, 28040 Madrid, SpainLaboratoire de Glaciologie, Université Libre de Bruxelles, Brussels, BelgiumDepartamento de Física de la Tierra y Astrofísica, Universidad Complutense de Madrid, Facultad de Ciencias Físicas, 28040 Madrid, SpainInstituto de Geociencias, Consejo Superior de Investigaciones Científicas, Universidad Complutense de Madrid, 28040 Madrid, SpainDepartamento de Física de la Tierra y Astrofísica, Universidad Complutense de Madrid, Facultad de Ciencias Físicas, 28040 Madrid, SpainInstituto de Geociencias, Consejo Superior de Investigaciones Científicas, Universidad Complutense de Madrid, 28040 Madrid, SpainEarth System Analysis, Potsdam Institute for Climate Impact Research, 14473 Potsdam, Germany<p>In the last decades, great effort has been made to reconstruct the Laurentide Ice Sheet (LIS) during the Last Glacial Maximum (LGM; ca. 21 000 years before present, 21 kyr ago). Uncertainties underlying its modelling have led to notable differences in fundamental features such as its maximum elevation, extent and total volume. As a result, the uncertainty in ice dynamics and thus in ice extent, volume and ice stream stability remains large. We herein use a higher-order three-dimensional ice sheet model to simulate the LIS under LGM boundary conditions for a number of basal friction formulations of varying complexity. Their consequences for the Laurentide ice streams, configuration, extent and volume are explicitly quantified. Total volume and ice extent generally reach a constant equilibrium value that falls close to prior LIS reconstructions. Simulations exhibit high sensitivity to the dependency of the basal shear stress on the sliding velocity. In particular, a regularised Coulomb friction formulation appears to be the best choice in terms of ice volume and ice stream realism. Pronounced differences are found when the basal friction stress is thermomechanically coupled: the base remains colder, and the LIS volume is lower than in the purely mechanical friction scenario counterpart. Thermomechanical coupling is fundamental for producing rapid ice streaming, yet it leads to a similar ice distribution overall.</p>https://tc.copernicus.org/articles/17/2139/2023/tc-17-2139-2023.pdf |
| spellingShingle | D. Moreno-Parada D. Moreno-Parada J. Alvarez-Solas J. Alvarez-Solas J. Blasco J. Blasco J. Blasco M. Montoya M. Montoya A. Robinson A. Robinson A. Robinson Simulating the Laurentide Ice Sheet of the Last Glacial Maximum The Cryosphere |
| title | Simulating the Laurentide Ice Sheet of the Last Glacial Maximum |
| title_full | Simulating the Laurentide Ice Sheet of the Last Glacial Maximum |
| title_fullStr | Simulating the Laurentide Ice Sheet of the Last Glacial Maximum |
| title_full_unstemmed | Simulating the Laurentide Ice Sheet of the Last Glacial Maximum |
| title_short | Simulating the Laurentide Ice Sheet of the Last Glacial Maximum |
| title_sort | simulating the laurentide ice sheet of the last glacial maximum |
| url | https://tc.copernicus.org/articles/17/2139/2023/tc-17-2139-2023.pdf |
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