Inferring forms of glacier slip laws from estimates of ice-bed separation during glacier slip
Sea-level projections depend sensitively on the parameterization used for basal slip in glacier flow models. During slip over rock-beds, ice-bed separation increases with slip velocity and basal water pressure. We present a method for using these variables and measured bed topography to estimate the...
Published in: | Journal of Glaciology |
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Language: | English |
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Cambridge University Press
2023
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Online Access: | https://doi.org/10.1017/jog.2022.63 https://doaj.org/article/1babfa244280441988a293ca2d20d2cb |
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ftdoajarticles:oai:doaj.org/article:1babfa244280441988a293ca2d20d2cb 2023-05-15T16:57:35+02:00 Inferring forms of glacier slip laws from estimates of ice-bed separation during glacier slip Jacob B. Woodard Lucas K. Zoet Neal R. Iverson Christian Helanow 2023-04-01T00:00:00Z https://doi.org/10.1017/jog.2022.63 https://doaj.org/article/1babfa244280441988a293ca2d20d2cb EN eng Cambridge University Press https://www.cambridge.org/core/product/identifier/S0022143022000636/type/journal_article https://doaj.org/toc/0022-1430 https://doaj.org/toc/1727-5652 doi:10.1017/jog.2022.63 0022-1430 1727-5652 https://doaj.org/article/1babfa244280441988a293ca2d20d2cb Journal of Glaciology, Vol 69, Pp 324-332 (2023) Glacier flow mountain glaciers subglacial processes Environmental sciences GE1-350 Meteorology. Climatology QC851-999 article 2023 ftdoajarticles https://doi.org/10.1017/jog.2022.63 2023-03-19T01:31:51Z Sea-level projections depend sensitively on the parameterization used for basal slip in glacier flow models. During slip over rock-beds, ice-bed separation increases with slip velocity and basal water pressure. We present a method for using these variables and measured bed topography to estimate the average bed slope in contact with ice, ${\bar m}$. Three-dimensional numerical modeling of slip over small areas of former beds has shown that changes in ${\bar m}$ with increasing slip velocity and water pressure mimic changes in basal drag. Computed values of ${\bar m}$ can thus provide the form of the slip law that relates drag to velocity and water pressure, avoiding computationally expensive numerical modeling. The method is applied to 618 sections from four former glacier beds. Results generally show an increase in ${\bar m}$, and hence inferred basal drag, with slip velocity up to a limiting value, consistent with a regularized Coulomb slip law. Article in Journal/Newspaper Journal of Glaciology Directory of Open Access Journals: DOAJ Articles Journal of Glaciology 69 274 324 332 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Glacier flow mountain glaciers subglacial processes Environmental sciences GE1-350 Meteorology. Climatology QC851-999 |
spellingShingle |
Glacier flow mountain glaciers subglacial processes Environmental sciences GE1-350 Meteorology. Climatology QC851-999 Jacob B. Woodard Lucas K. Zoet Neal R. Iverson Christian Helanow Inferring forms of glacier slip laws from estimates of ice-bed separation during glacier slip |
topic_facet |
Glacier flow mountain glaciers subglacial processes Environmental sciences GE1-350 Meteorology. Climatology QC851-999 |
description |
Sea-level projections depend sensitively on the parameterization used for basal slip in glacier flow models. During slip over rock-beds, ice-bed separation increases with slip velocity and basal water pressure. We present a method for using these variables and measured bed topography to estimate the average bed slope in contact with ice, ${\bar m}$. Three-dimensional numerical modeling of slip over small areas of former beds has shown that changes in ${\bar m}$ with increasing slip velocity and water pressure mimic changes in basal drag. Computed values of ${\bar m}$ can thus provide the form of the slip law that relates drag to velocity and water pressure, avoiding computationally expensive numerical modeling. The method is applied to 618 sections from four former glacier beds. Results generally show an increase in ${\bar m}$, and hence inferred basal drag, with slip velocity up to a limiting value, consistent with a regularized Coulomb slip law. |
format |
Article in Journal/Newspaper |
author |
Jacob B. Woodard Lucas K. Zoet Neal R. Iverson Christian Helanow |
author_facet |
Jacob B. Woodard Lucas K. Zoet Neal R. Iverson Christian Helanow |
author_sort |
Jacob B. Woodard |
title |
Inferring forms of glacier slip laws from estimates of ice-bed separation during glacier slip |
title_short |
Inferring forms of glacier slip laws from estimates of ice-bed separation during glacier slip |
title_full |
Inferring forms of glacier slip laws from estimates of ice-bed separation during glacier slip |
title_fullStr |
Inferring forms of glacier slip laws from estimates of ice-bed separation during glacier slip |
title_full_unstemmed |
Inferring forms of glacier slip laws from estimates of ice-bed separation during glacier slip |
title_sort |
inferring forms of glacier slip laws from estimates of ice-bed separation during glacier slip |
publisher |
Cambridge University Press |
publishDate |
2023 |
url |
https://doi.org/10.1017/jog.2022.63 https://doaj.org/article/1babfa244280441988a293ca2d20d2cb |
genre |
Journal of Glaciology |
genre_facet |
Journal of Glaciology |
op_source |
Journal of Glaciology, Vol 69, Pp 324-332 (2023) |
op_relation |
https://www.cambridge.org/core/product/identifier/S0022143022000636/type/journal_article https://doaj.org/toc/0022-1430 https://doaj.org/toc/1727-5652 doi:10.1017/jog.2022.63 0022-1430 1727-5652 https://doaj.org/article/1babfa244280441988a293ca2d20d2cb |
op_doi |
https://doi.org/10.1017/jog.2022.63 |
container_title |
Journal of Glaciology |
container_volume |
69 |
container_issue |
274 |
container_start_page |
324 |
op_container_end_page |
332 |
_version_ |
1766049147298775040 |