Sheet, stream, and shelf flow as progressive ice-bed uncoupling: Byrd Glacier, Antarctica and Jakobshavn Isbrae, Greenland
The first-order control of ice thickness and height above sea level is linked to the decreasing strength of ice-bed coupling along flowlines from an interior ice divide to the calving front of an ice shelf. Uncoupling progresses as a frozen bed progressively thaws for sheet flow, as a thawed bed is...
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ftcopernicus:oai:publications.copernicus.org:tc29576 2023-05-15T13:54:27+02:00 Sheet, stream, and shelf flow as progressive ice-bed uncoupling: Byrd Glacier, Antarctica and Jakobshavn Isbrae, Greenland Hughes, T. Sargent, A. Fastook, J. Purdon, K. Li, J. Yan, J.-B. Gogineni, S. 2018-09-27 application/pdf https://doi.org/10.5194/tc-10-193-2016 https://tc.copernicus.org/articles/10/193/2016/ eng eng doi:10.5194/tc-10-193-2016 https://tc.copernicus.org/articles/10/193/2016/ eISSN: 1994-0424 Text 2018 ftcopernicus https://doi.org/10.5194/tc-10-193-2016 2020-07-20T16:24:17Z The first-order control of ice thickness and height above sea level is linked to the decreasing strength of ice-bed coupling along flowlines from an interior ice divide to the calving front of an ice shelf. Uncoupling progresses as a frozen bed progressively thaws for sheet flow, as a thawed bed is progressively drowned for stream flow, and as lateral and/or local grounding vanish for shelf flow. This can reduce ice thicknesses by 90 % and ice elevations by 99 % along flowlines. Original work presented here includes (1) replacing flow and sliding laws for sheet flow with upper and lower yield stresses for creep in cold overlying ice and basal ice sliding over deforming till, respectively, (2) replacing integrating the Navier–Stokes equations for stream flow with geometrical solutions to the force balance, and (3) including resistance to shelf flow caused by lateral confinement in a fjord and local grounding at ice rumples and ice rises. A comparison is made between our approach and two approaches based on continuum mechanics. Applications are made to Byrd Glacier in Antarctica and Jakobshavn Isbrae in Greenland. Text Antarc* Antarctica Byrd Glacier glacier Greenland Ice Shelf Jakobshavn Copernicus Publications: E-Journals Byrd Byrd Glacier ENVELOPE(160.333,160.333,-80.250,-80.250) Greenland The Cryosphere 10 1 193 225 |
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Open Polar |
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Copernicus Publications: E-Journals |
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ftcopernicus |
language |
English |
description |
The first-order control of ice thickness and height above sea level is linked to the decreasing strength of ice-bed coupling along flowlines from an interior ice divide to the calving front of an ice shelf. Uncoupling progresses as a frozen bed progressively thaws for sheet flow, as a thawed bed is progressively drowned for stream flow, and as lateral and/or local grounding vanish for shelf flow. This can reduce ice thicknesses by 90 % and ice elevations by 99 % along flowlines. Original work presented here includes (1) replacing flow and sliding laws for sheet flow with upper and lower yield stresses for creep in cold overlying ice and basal ice sliding over deforming till, respectively, (2) replacing integrating the Navier–Stokes equations for stream flow with geometrical solutions to the force balance, and (3) including resistance to shelf flow caused by lateral confinement in a fjord and local grounding at ice rumples and ice rises. A comparison is made between our approach and two approaches based on continuum mechanics. Applications are made to Byrd Glacier in Antarctica and Jakobshavn Isbrae in Greenland. |
format |
Text |
author |
Hughes, T. Sargent, A. Fastook, J. Purdon, K. Li, J. Yan, J.-B. Gogineni, S. |
spellingShingle |
Hughes, T. Sargent, A. Fastook, J. Purdon, K. Li, J. Yan, J.-B. Gogineni, S. Sheet, stream, and shelf flow as progressive ice-bed uncoupling: Byrd Glacier, Antarctica and Jakobshavn Isbrae, Greenland |
author_facet |
Hughes, T. Sargent, A. Fastook, J. Purdon, K. Li, J. Yan, J.-B. Gogineni, S. |
author_sort |
Hughes, T. |
title |
Sheet, stream, and shelf flow as progressive ice-bed uncoupling: Byrd Glacier, Antarctica and Jakobshavn Isbrae, Greenland |
title_short |
Sheet, stream, and shelf flow as progressive ice-bed uncoupling: Byrd Glacier, Antarctica and Jakobshavn Isbrae, Greenland |
title_full |
Sheet, stream, and shelf flow as progressive ice-bed uncoupling: Byrd Glacier, Antarctica and Jakobshavn Isbrae, Greenland |
title_fullStr |
Sheet, stream, and shelf flow as progressive ice-bed uncoupling: Byrd Glacier, Antarctica and Jakobshavn Isbrae, Greenland |
title_full_unstemmed |
Sheet, stream, and shelf flow as progressive ice-bed uncoupling: Byrd Glacier, Antarctica and Jakobshavn Isbrae, Greenland |
title_sort |
sheet, stream, and shelf flow as progressive ice-bed uncoupling: byrd glacier, antarctica and jakobshavn isbrae, greenland |
publishDate |
2018 |
url |
https://doi.org/10.5194/tc-10-193-2016 https://tc.copernicus.org/articles/10/193/2016/ |
long_lat |
ENVELOPE(160.333,160.333,-80.250,-80.250) |
geographic |
Byrd Byrd Glacier Greenland |
geographic_facet |
Byrd Byrd Glacier Greenland |
genre |
Antarc* Antarctica Byrd Glacier glacier Greenland Ice Shelf Jakobshavn |
genre_facet |
Antarc* Antarctica Byrd Glacier glacier Greenland Ice Shelf Jakobshavn |
op_source |
eISSN: 1994-0424 |
op_relation |
doi:10.5194/tc-10-193-2016 https://tc.copernicus.org/articles/10/193/2016/ |
op_doi |
https://doi.org/10.5194/tc-10-193-2016 |
container_title |
The Cryosphere |
container_volume |
10 |
container_issue |
1 |
container_start_page |
193 |
op_container_end_page |
225 |
_version_ |
1766260344720719872 |