A boundary layer model for ice stream margins
International audience The majority of Antarctic ice is discharged via long and narrow fast-flowing ice streams. At ice stream margins, the rapid transition from the vertical shearing flow in the ice ridges surrounding the stream to a rapidly sliding plug flow in the stream itself leads to high stre...
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Online Access: | https://hal-insu.archives-ouvertes.fr/insu-01235613 https://doi.org/10.1017/jfm.2015.503 |
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ftunivnantes:oai:HAL:insu-01235613v1 2023-05-15T13:57:13+02:00 A boundary layer model for ice stream margins Haseloff, M. Schoof, C. Gagliardini, Olivier Department of Earth, Ocean and Atmospheric Sciences Vancouver (UBC EOAS) University of British Columbia (UBC) Université Grenoble Alpes 2016-2019 (UGA 2016-2019 ) Institut Universitaire de France (IUF) Ministère de l'Education nationale, de l’Enseignement supérieur et de la Recherche (M.E.N.E.S.R.) Laboratoire de glaciologie et géophysique de l'environnement (LGGE) Observatoire des Sciences de l'Univers de Grenoble (OSUG) Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS) 2015-10 https://hal-insu.archives-ouvertes.fr/insu-01235613 https://doi.org/10.1017/jfm.2015.503 en eng HAL CCSD Elsevier info:eu-repo/semantics/altIdentifier/doi/10.1017/jfm.2015.503 insu-01235613 https://hal-insu.archives-ouvertes.fr/insu-01235613 doi:10.1017/jfm.2015.503 ISSN: 0997-7546 EISSN: 1873-7390 European Journal of Mechanics - B/Fluids https://hal-insu.archives-ouvertes.fr/insu-01235613 European Journal of Mechanics - B/Fluids, 2015, 781, pp.353-387. ⟨10.1017/jfm.2015.503⟩ [SDE]Environmental Sciences info:eu-repo/semantics/article Journal articles 2015 ftunivnantes https://doi.org/10.1017/jfm.2015.503 2023-03-01T06:27:29Z International audience The majority of Antarctic ice is discharged via long and narrow fast-flowing ice streams. At ice stream margins, the rapid transition from the vertical shearing flow in the ice ridges surrounding the stream to a rapidly sliding plug flow in the stream itself leads to high stress concentrations and a velocity field whose form is non-trivial to determine. In this paper, we develop a boundary layer theory for this narrow region separating a lubrication-type ice ridge flow and a membrane-type ice stream flow. This allows us to derive jump conditions for the outer models describing ridge and stream self-consistently. Much of our focus is, however, on determining the velocity and shear heating fields in the margin itself. Ice stream margins have been observed to change position over time, with potentially significant implications for ice stream discharge. Our boundary layer model allows us to extend previous work that has determined rates of margin migration from a balance between shear heating in the margin and the cooling effect of margin migration into the colder ice of the surrounding ice ridge. Solving for the transverse velocity field in the margin allows us to include the effect of advection due to lateral inflow of ice from the ridge on margin migration, and we demonstrate that this reduces the rate of margin migration, as previously speculated. Article in Journal/Newspaper Antarc* Antarctic Université de Nantes: HAL-UNIV-NANTES Antarctic Journal of Fluid Mechanics 781 353 387 |
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Open Polar |
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Université de Nantes: HAL-UNIV-NANTES |
op_collection_id |
ftunivnantes |
language |
English |
topic |
[SDE]Environmental Sciences |
spellingShingle |
[SDE]Environmental Sciences Haseloff, M. Schoof, C. Gagliardini, Olivier A boundary layer model for ice stream margins |
topic_facet |
[SDE]Environmental Sciences |
description |
International audience The majority of Antarctic ice is discharged via long and narrow fast-flowing ice streams. At ice stream margins, the rapid transition from the vertical shearing flow in the ice ridges surrounding the stream to a rapidly sliding plug flow in the stream itself leads to high stress concentrations and a velocity field whose form is non-trivial to determine. In this paper, we develop a boundary layer theory for this narrow region separating a lubrication-type ice ridge flow and a membrane-type ice stream flow. This allows us to derive jump conditions for the outer models describing ridge and stream self-consistently. Much of our focus is, however, on determining the velocity and shear heating fields in the margin itself. Ice stream margins have been observed to change position over time, with potentially significant implications for ice stream discharge. Our boundary layer model allows us to extend previous work that has determined rates of margin migration from a balance between shear heating in the margin and the cooling effect of margin migration into the colder ice of the surrounding ice ridge. Solving for the transverse velocity field in the margin allows us to include the effect of advection due to lateral inflow of ice from the ridge on margin migration, and we demonstrate that this reduces the rate of margin migration, as previously speculated. |
author2 |
Department of Earth, Ocean and Atmospheric Sciences Vancouver (UBC EOAS) University of British Columbia (UBC) Université Grenoble Alpes 2016-2019 (UGA 2016-2019 ) Institut Universitaire de France (IUF) Ministère de l'Education nationale, de l’Enseignement supérieur et de la Recherche (M.E.N.E.S.R.) Laboratoire de glaciologie et géophysique de l'environnement (LGGE) Observatoire des Sciences de l'Univers de Grenoble (OSUG) Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS) |
format |
Article in Journal/Newspaper |
author |
Haseloff, M. Schoof, C. Gagliardini, Olivier |
author_facet |
Haseloff, M. Schoof, C. Gagliardini, Olivier |
author_sort |
Haseloff, M. |
title |
A boundary layer model for ice stream margins |
title_short |
A boundary layer model for ice stream margins |
title_full |
A boundary layer model for ice stream margins |
title_fullStr |
A boundary layer model for ice stream margins |
title_full_unstemmed |
A boundary layer model for ice stream margins |
title_sort |
boundary layer model for ice stream margins |
publisher |
HAL CCSD |
publishDate |
2015 |
url |
https://hal-insu.archives-ouvertes.fr/insu-01235613 https://doi.org/10.1017/jfm.2015.503 |
geographic |
Antarctic |
geographic_facet |
Antarctic |
genre |
Antarc* Antarctic |
genre_facet |
Antarc* Antarctic |
op_source |
ISSN: 0997-7546 EISSN: 1873-7390 European Journal of Mechanics - B/Fluids https://hal-insu.archives-ouvertes.fr/insu-01235613 European Journal of Mechanics - B/Fluids, 2015, 781, pp.353-387. ⟨10.1017/jfm.2015.503⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1017/jfm.2015.503 insu-01235613 https://hal-insu.archives-ouvertes.fr/insu-01235613 doi:10.1017/jfm.2015.503 |
op_doi |
https://doi.org/10.1017/jfm.2015.503 |
container_title |
Journal of Fluid Mechanics |
container_volume |
781 |
container_start_page |
353 |
op_container_end_page |
387 |
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1766264815510093824 |