A shallow approximation for ice streams sliding over strong beds

Ice streams are regions of rapid ice sheet flow characterised by a high degree of sliding over a deforming bed. The shallow shelf approximation (SSA) provides a convenient way to obtain closed-form approximations of the velocity and flux in a rapidly sliding ice stream when the basal drag is much le...

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Main Authors: Katarzyna L. P. Warburton, Duncan R. Hewitt, Colin R. Meyer, Jerome A. Neufeld
Format: Article
Language:English
Published: Cambridge University Press 2023-12-01
Series:Journal of Glaciology
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Online Access:https://www.cambridge.org/core/product/identifier/S0022143023000473/type/journal_article
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author Katarzyna L. P. Warburton
Duncan R. Hewitt
Colin R. Meyer
Jerome A. Neufeld
author_facet Katarzyna L. P. Warburton
Duncan R. Hewitt
Colin R. Meyer
Jerome A. Neufeld
author_sort Katarzyna L. P. Warburton
collection DOAJ
description Ice streams are regions of rapid ice sheet flow characterised by a high degree of sliding over a deforming bed. The shallow shelf approximation (SSA) provides a convenient way to obtain closed-form approximations of the velocity and flux in a rapidly sliding ice stream when the basal drag is much less than the driving stress. However, the validity of the SSA approximation breaks down when the magnitude of the basal drag increases. Here we find a more accurate expression for the velocity and flux in this transitional regime before vertical deformation fully dominates, in agreement with numerical results. The closed-form expressions we derive can be incorporated into wider modelling efforts to yield a better characterisation of ice stream dynamics, and inform the use of the SSA in large-scale simulations.
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id doaj-art-7e6b45e837644611a3fac8d9fac913f2
institution OA Journals
issn 0022-1430
1727-5652
language English
publishDate 2023-12-01
publisher Cambridge University Press
record_format Article
series Journal of Glaciology
spelling doaj-art-7e6b45e837644611a3fac8d9fac913f22025-08-20T02:33:44ZengCambridge University PressJournal of Glaciology0022-14301727-56522023-12-01691634164510.1017/jog.2023.47A shallow approximation for ice streams sliding over strong bedsKatarzyna L. P. Warburton0https://orcid.org/0000-0002-5537-0557Duncan R. Hewitt1Colin R. Meyer2Jerome A. Neufeld3Thayer School of Engineering, Dartmouth College, Hanover, NH, USA Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Cambridge, UKDepartment of Mathematics, University College London, London, UKThayer School of Engineering, Dartmouth College, Hanover, NH, USADepartment of Earth Sciences, University of Cambridge, Cambridge, UK Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Cambridge, UK Institute for Energy and Environmental Flows, University of Cambridge, Cambridge, UKIce streams are regions of rapid ice sheet flow characterised by a high degree of sliding over a deforming bed. The shallow shelf approximation (SSA) provides a convenient way to obtain closed-form approximations of the velocity and flux in a rapidly sliding ice stream when the basal drag is much less than the driving stress. However, the validity of the SSA approximation breaks down when the magnitude of the basal drag increases. Here we find a more accurate expression for the velocity and flux in this transitional regime before vertical deformation fully dominates, in agreement with numerical results. The closed-form expressions we derive can be incorporated into wider modelling efforts to yield a better characterisation of ice stream dynamics, and inform the use of the SSA in large-scale simulations.https://www.cambridge.org/core/product/identifier/S0022143023000473/type/journal_articleglacier flowglacial rheologyice dynamicsice streams
spellingShingle Katarzyna L. P. Warburton
Duncan R. Hewitt
Colin R. Meyer
Jerome A. Neufeld
A shallow approximation for ice streams sliding over strong beds
Journal of Glaciology
glacier flow
glacial rheology
ice dynamics
ice streams
title A shallow approximation for ice streams sliding over strong beds
title_full A shallow approximation for ice streams sliding over strong beds
title_fullStr A shallow approximation for ice streams sliding over strong beds
title_full_unstemmed A shallow approximation for ice streams sliding over strong beds
title_short A shallow approximation for ice streams sliding over strong beds
title_sort shallow approximation for ice streams sliding over strong beds
topic glacier flow
glacial rheology
ice dynamics
ice streams
url https://www.cambridge.org/core/product/identifier/S0022143023000473/type/journal_article
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