Spatiotemporal Dynamics of Ice Streams Due to a Triple-Valued Sliding Law
We show that a triple-valued sliding law can be heuristically motivated by the transverse spatial structure of an ice-stream velocity field using a simple one-dimensional model. We then demonstrate that such a sliding law can lead to some interesting stream-like patterns and time-oscillatory solutio...
Published in: | Journal of Fluid Mechanics |
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Cambridge University Press
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Online Access: | http://nrs.harvard.edu/urn-3:HUL.InstRepos:3445991 https://doi.org/10.1017/S0022112009991406 |
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ftharvardudash:oai:dash.harvard.edu:1/3445991 2023-05-15T16:41:05+02:00 Spatiotemporal Dynamics of Ice Streams Due to a Triple-Valued Sliding Law Sayag, Roiy Tziperman, Eli 2009 application/pdf http://nrs.harvard.edu/urn-3:HUL.InstRepos:3445991 https://doi.org/10.1017/S0022112009991406 en_US eng Cambridge University Press doi:10.1017/S0022112009991406 http://www.damtp.cam.ac.uk/user/rs620/publications/004-Sayag-Tziperman-2009.pdf Journal of Fluid Mechanics Sayag, Roiy, and Eli Tziperman. 2009. Spatiotemporal dynamics of ice streams due to a triple valued sliding law. Journal of Fluid Mechanics 640: 483-505. 0022-1120 http://nrs.harvard.edu/urn-3:HUL.InstRepos:3445991 ice sheets instability low-Reynolds-number flows Journal Article 2009 ftharvardudash https://doi.org/10.1017/S0022112009991406 2022-04-04T12:36:40Z We show that a triple-valued sliding law can be heuristically motivated by the transverse spatial structure of an ice-stream velocity field using a simple one-dimensional model. We then demonstrate that such a sliding law can lead to some interesting stream-like patterns and time-oscillatory solutions. We find a generation of rapid stream-like solutions within a slow ice-sheet flow, separated by narrow internal boundary layers (shear margins), and analyse numerical simulations in two horizontal dimensions over a homogeneous bed and including longitudinal shear stresses. Different qualitative behaviours are obtained by changing a single physical parameter, a mass source magnitude, leading to changes from a slow creeping flow to a relaxation oscillation of the stream pattern, and to steady ice-stream-like solution. We show that the adjustment of the ice-flow shear margins to changes in the driving stress in the one-dimensional approximation is governed by a form of the Ginzburg–Landau equation and use stability analysis to understand this adjustment. In the model analysed here, the width scale of the stream is not set spontaneously by the ice flow dynamics, but rather, it is related to the mass source intensity and spatial distribution. Earth and Planetary Sciences Version of Record Article in Journal/Newspaper Ice Sheet Harvard University: DASH - Digital Access to Scholarship at Harvard Journal of Fluid Mechanics 640 483 505 |
institution |
Open Polar |
collection |
Harvard University: DASH - Digital Access to Scholarship at Harvard |
op_collection_id |
ftharvardudash |
language |
English |
topic |
ice sheets instability low-Reynolds-number flows |
spellingShingle |
ice sheets instability low-Reynolds-number flows Sayag, Roiy Tziperman, Eli Spatiotemporal Dynamics of Ice Streams Due to a Triple-Valued Sliding Law |
topic_facet |
ice sheets instability low-Reynolds-number flows |
description |
We show that a triple-valued sliding law can be heuristically motivated by the transverse spatial structure of an ice-stream velocity field using a simple one-dimensional model. We then demonstrate that such a sliding law can lead to some interesting stream-like patterns and time-oscillatory solutions. We find a generation of rapid stream-like solutions within a slow ice-sheet flow, separated by narrow internal boundary layers (shear margins), and analyse numerical simulations in two horizontal dimensions over a homogeneous bed and including longitudinal shear stresses. Different qualitative behaviours are obtained by changing a single physical parameter, a mass source magnitude, leading to changes from a slow creeping flow to a relaxation oscillation of the stream pattern, and to steady ice-stream-like solution. We show that the adjustment of the ice-flow shear margins to changes in the driving stress in the one-dimensional approximation is governed by a form of the Ginzburg–Landau equation and use stability analysis to understand this adjustment. In the model analysed here, the width scale of the stream is not set spontaneously by the ice flow dynamics, but rather, it is related to the mass source intensity and spatial distribution. Earth and Planetary Sciences Version of Record |
format |
Article in Journal/Newspaper |
author |
Sayag, Roiy Tziperman, Eli |
author_facet |
Sayag, Roiy Tziperman, Eli |
author_sort |
Sayag, Roiy |
title |
Spatiotemporal Dynamics of Ice Streams Due to a Triple-Valued Sliding Law |
title_short |
Spatiotemporal Dynamics of Ice Streams Due to a Triple-Valued Sliding Law |
title_full |
Spatiotemporal Dynamics of Ice Streams Due to a Triple-Valued Sliding Law |
title_fullStr |
Spatiotemporal Dynamics of Ice Streams Due to a Triple-Valued Sliding Law |
title_full_unstemmed |
Spatiotemporal Dynamics of Ice Streams Due to a Triple-Valued Sliding Law |
title_sort |
spatiotemporal dynamics of ice streams due to a triple-valued sliding law |
publisher |
Cambridge University Press |
publishDate |
2009 |
url |
http://nrs.harvard.edu/urn-3:HUL.InstRepos:3445991 https://doi.org/10.1017/S0022112009991406 |
genre |
Ice Sheet |
genre_facet |
Ice Sheet |
op_relation |
doi:10.1017/S0022112009991406 http://www.damtp.cam.ac.uk/user/rs620/publications/004-Sayag-Tziperman-2009.pdf Journal of Fluid Mechanics Sayag, Roiy, and Eli Tziperman. 2009. Spatiotemporal dynamics of ice streams due to a triple valued sliding law. Journal of Fluid Mechanics 640: 483-505. 0022-1120 http://nrs.harvard.edu/urn-3:HUL.InstRepos:3445991 |
op_doi |
https://doi.org/10.1017/S0022112009991406 |
container_title |
Journal of Fluid Mechanics |
container_volume |
640 |
container_start_page |
483 |
op_container_end_page |
505 |
_version_ |
1766031520046252032 |