Two-Dimensional, Time-dependent Modelling of an Arbitrarily Shaped Ice Mass with the Finite-Element Technique
Abstract The two-dimensional, time-dependent flow of an arbitrarily shaped ice mass can be successfully modeled with the finite-element technique on a small computer. Methods developed for automatically generating the mesh data greatly simplify the data preparation and optimize the numerical simulat...
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Language: | English |
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Cambridge University Press (CUP)
1985
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Online Access: | http://dx.doi.org/10.1017/s0022143000006699 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000006699 |
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crcambridgeupr:10.1017/s0022143000006699 2024-03-03T08:46:09+00:00 Two-Dimensional, Time-dependent Modelling of an Arbitrarily Shaped Ice Mass with the Finite-Element Technique Hodge, Steven M. 1985 http://dx.doi.org/10.1017/s0022143000006699 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000006699 en eng Cambridge University Press (CUP) Journal of Glaciology volume 31, issue 109, page 350-359 ISSN 0022-1430 1727-5652 Earth-Surface Processes journal-article 1985 crcambridgeupr https://doi.org/10.1017/s0022143000006699 2024-02-08T08:39:08Z Abstract The two-dimensional, time-dependent flow of an arbitrarily shaped ice mass can be successfully modeled with the finite-element technique on a small computer. Methods developed for automatically generating the mesh data greatly simplify the data preparation and optimize the numerical simulations. Using quadratic basis functions permits the flow to be approximated quite adequately by only two element rows (five nodes vertically). Mixed-order basis functions, however, must be used so that numerical oscillations do not set in, and the ends of the ice mass, where the thickness tends to zero, must be treated carefully. Time simulations to a steady-state condition are necessary to test such numerical models adequately. South Cascade Glacier, Washington, is currently close to equilibrium. A bedrock sill dominates the bed topography in the lower half of the glacier, rising to a height of about 20% of the ice thickness. This sill produces a maximum increase in the overall thickness of about 6–7% compared to what the thickness would have been if the sill were not present. Finally, this glacier does not appear to be sliding much, if at all, despite its maritime alpine environment. This could help explain the difficulties encountered when trying to measure sliding and basal water pressures on the same glacier (Hodge, 1979), or it could imply that drag exerted by the valley walls has a significantly greater effect than conventional shape-factor concepts imply. Article in Journal/Newspaper Journal of Glaciology Cambridge University Press Cascade Glacier ENVELOPE(-140.504,-140.504,60.249,60.249) Journal of Glaciology 31 109 350 359 |
institution |
Open Polar |
collection |
Cambridge University Press |
op_collection_id |
crcambridgeupr |
language |
English |
topic |
Earth-Surface Processes |
spellingShingle |
Earth-Surface Processes Hodge, Steven M. Two-Dimensional, Time-dependent Modelling of an Arbitrarily Shaped Ice Mass with the Finite-Element Technique |
topic_facet |
Earth-Surface Processes |
description |
Abstract The two-dimensional, time-dependent flow of an arbitrarily shaped ice mass can be successfully modeled with the finite-element technique on a small computer. Methods developed for automatically generating the mesh data greatly simplify the data preparation and optimize the numerical simulations. Using quadratic basis functions permits the flow to be approximated quite adequately by only two element rows (five nodes vertically). Mixed-order basis functions, however, must be used so that numerical oscillations do not set in, and the ends of the ice mass, where the thickness tends to zero, must be treated carefully. Time simulations to a steady-state condition are necessary to test such numerical models adequately. South Cascade Glacier, Washington, is currently close to equilibrium. A bedrock sill dominates the bed topography in the lower half of the glacier, rising to a height of about 20% of the ice thickness. This sill produces a maximum increase in the overall thickness of about 6–7% compared to what the thickness would have been if the sill were not present. Finally, this glacier does not appear to be sliding much, if at all, despite its maritime alpine environment. This could help explain the difficulties encountered when trying to measure sliding and basal water pressures on the same glacier (Hodge, 1979), or it could imply that drag exerted by the valley walls has a significantly greater effect than conventional shape-factor concepts imply. |
format |
Article in Journal/Newspaper |
author |
Hodge, Steven M. |
author_facet |
Hodge, Steven M. |
author_sort |
Hodge, Steven M. |
title |
Two-Dimensional, Time-dependent Modelling of an Arbitrarily Shaped Ice Mass with the Finite-Element Technique |
title_short |
Two-Dimensional, Time-dependent Modelling of an Arbitrarily Shaped Ice Mass with the Finite-Element Technique |
title_full |
Two-Dimensional, Time-dependent Modelling of an Arbitrarily Shaped Ice Mass with the Finite-Element Technique |
title_fullStr |
Two-Dimensional, Time-dependent Modelling of an Arbitrarily Shaped Ice Mass with the Finite-Element Technique |
title_full_unstemmed |
Two-Dimensional, Time-dependent Modelling of an Arbitrarily Shaped Ice Mass with the Finite-Element Technique |
title_sort |
two-dimensional, time-dependent modelling of an arbitrarily shaped ice mass with the finite-element technique |
publisher |
Cambridge University Press (CUP) |
publishDate |
1985 |
url |
http://dx.doi.org/10.1017/s0022143000006699 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000006699 |
long_lat |
ENVELOPE(-140.504,-140.504,60.249,60.249) |
geographic |
Cascade Glacier |
geographic_facet |
Cascade Glacier |
genre |
Journal of Glaciology |
genre_facet |
Journal of Glaciology |
op_source |
Journal of Glaciology volume 31, issue 109, page 350-359 ISSN 0022-1430 1727-5652 |
op_doi |
https://doi.org/10.1017/s0022143000006699 |
container_title |
Journal of Glaciology |
container_volume |
31 |
container_issue |
109 |
container_start_page |
350 |
op_container_end_page |
359 |
_version_ |
1792502118564757504 |