Sliding of temperate basal ice on a rough, hard bed: creep mechanisms, pressure melting, and implications for ice streaming
Basal ice motion is crucial to ice dynamics of ice sheets. The classic Weertman model for basal sliding over bedrock obstacles proposes that sliding velocity is controlled by pressure melting and/or ductile flow, whichever is the fastest; it further assumes that pressure melting is limited by heat f...
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European Geosciences Union
2016
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Online Access: | http://nora.nerc.ac.uk/id/eprint/514387/ https://nora.nerc.ac.uk/id/eprint/514387/1/Krabbendam_2016_Sliding_temperate_ice_Cryosphere.pdf https://doi.org/10.5194/tc-10-1915-2016 |
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ftnerc:oai:nora.nerc.ac.uk:514387 2023-05-15T16:29:28+02:00 Sliding of temperate basal ice on a rough, hard bed: creep mechanisms, pressure melting, and implications for ice streaming Krabbendam, Maarten 2016 text http://nora.nerc.ac.uk/id/eprint/514387/ https://nora.nerc.ac.uk/id/eprint/514387/1/Krabbendam_2016_Sliding_temperate_ice_Cryosphere.pdf https://doi.org/10.5194/tc-10-1915-2016 en eng European Geosciences Union https://nora.nerc.ac.uk/id/eprint/514387/1/Krabbendam_2016_Sliding_temperate_ice_Cryosphere.pdf Krabbendam, Maarten. 2016 Sliding of temperate basal ice on a rough, hard bed: creep mechanisms, pressure melting, and implications for ice streaming. The Cryosphere, 10 (5). 1915-1932. https://doi.org/10.5194/tc-10-1915-2016 <https://doi.org/10.5194/tc-10-1915-2016> cc_by CC-BY Publication - Article PeerReviewed 2016 ftnerc https://doi.org/10.5194/tc-10-1915-2016 2023-02-04T19:43:29Z Basal ice motion is crucial to ice dynamics of ice sheets. The classic Weertman model for basal sliding over bedrock obstacles proposes that sliding velocity is controlled by pressure melting and/or ductile flow, whichever is the fastest; it further assumes that pressure melting is limited by heat flow through the obstacle and ductile flow is controlled by standard power-law creep. These last two assumptions, however, are not applicable if a substantial basal layer of temperate (T � Tmelt/ ice is present. In that case, frictional melting can produce excess basal meltwater and efficient water flow, leading to near-thermal equilibrium. High-temperature ice creep experiments have shown a sharp weakening of a factor 5–10 close to Tmelt, suggesting standard power-law creep does not operate due to a switch to melt-assisted creep with a possible component of grain boundary melting. Pressure melting is controlled by meltwater production, heat advection by flowing meltwater to the next obstacle and heat conduction through ice/rock over half the obstacle height. No heat flow through the obstacle is required. Ice streaming over a rough, hard bed, as possibly in the Northeast Greenland Ice Stream, may be explained by enhanced basal motion in a thick temperate ice layer. Article in Journal/Newspaper Greenland The Cryosphere Natural Environment Research Council: NERC Open Research Archive Greenland Weertman ENVELOPE(-67.753,-67.753,-66.972,-66.972) The Cryosphere 10 5 1915 1932 |
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Open Polar |
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Natural Environment Research Council: NERC Open Research Archive |
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ftnerc |
language |
English |
description |
Basal ice motion is crucial to ice dynamics of ice sheets. The classic Weertman model for basal sliding over bedrock obstacles proposes that sliding velocity is controlled by pressure melting and/or ductile flow, whichever is the fastest; it further assumes that pressure melting is limited by heat flow through the obstacle and ductile flow is controlled by standard power-law creep. These last two assumptions, however, are not applicable if a substantial basal layer of temperate (T � Tmelt/ ice is present. In that case, frictional melting can produce excess basal meltwater and efficient water flow, leading to near-thermal equilibrium. High-temperature ice creep experiments have shown a sharp weakening of a factor 5–10 close to Tmelt, suggesting standard power-law creep does not operate due to a switch to melt-assisted creep with a possible component of grain boundary melting. Pressure melting is controlled by meltwater production, heat advection by flowing meltwater to the next obstacle and heat conduction through ice/rock over half the obstacle height. No heat flow through the obstacle is required. Ice streaming over a rough, hard bed, as possibly in the Northeast Greenland Ice Stream, may be explained by enhanced basal motion in a thick temperate ice layer. |
format |
Article in Journal/Newspaper |
author |
Krabbendam, Maarten |
spellingShingle |
Krabbendam, Maarten Sliding of temperate basal ice on a rough, hard bed: creep mechanisms, pressure melting, and implications for ice streaming |
author_facet |
Krabbendam, Maarten |
author_sort |
Krabbendam, Maarten |
title |
Sliding of temperate basal ice on a rough, hard bed: creep mechanisms, pressure melting, and implications for ice streaming |
title_short |
Sliding of temperate basal ice on a rough, hard bed: creep mechanisms, pressure melting, and implications for ice streaming |
title_full |
Sliding of temperate basal ice on a rough, hard bed: creep mechanisms, pressure melting, and implications for ice streaming |
title_fullStr |
Sliding of temperate basal ice on a rough, hard bed: creep mechanisms, pressure melting, and implications for ice streaming |
title_full_unstemmed |
Sliding of temperate basal ice on a rough, hard bed: creep mechanisms, pressure melting, and implications for ice streaming |
title_sort |
sliding of temperate basal ice on a rough, hard bed: creep mechanisms, pressure melting, and implications for ice streaming |
publisher |
European Geosciences Union |
publishDate |
2016 |
url |
http://nora.nerc.ac.uk/id/eprint/514387/ https://nora.nerc.ac.uk/id/eprint/514387/1/Krabbendam_2016_Sliding_temperate_ice_Cryosphere.pdf https://doi.org/10.5194/tc-10-1915-2016 |
long_lat |
ENVELOPE(-67.753,-67.753,-66.972,-66.972) |
geographic |
Greenland Weertman |
geographic_facet |
Greenland Weertman |
genre |
Greenland The Cryosphere |
genre_facet |
Greenland The Cryosphere |
op_relation |
https://nora.nerc.ac.uk/id/eprint/514387/1/Krabbendam_2016_Sliding_temperate_ice_Cryosphere.pdf Krabbendam, Maarten. 2016 Sliding of temperate basal ice on a rough, hard bed: creep mechanisms, pressure melting, and implications for ice streaming. The Cryosphere, 10 (5). 1915-1932. https://doi.org/10.5194/tc-10-1915-2016 <https://doi.org/10.5194/tc-10-1915-2016> |
op_rights |
cc_by |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.5194/tc-10-1915-2016 |
container_title |
The Cryosphere |
container_volume |
10 |
container_issue |
5 |
container_start_page |
1915 |
op_container_end_page |
1932 |
_version_ |
1766019173473845248 |