Glacier sliding, seismicity and sediment entrainment
The evolution of glaciers and ice sheets depends on processes in the subglacial environment. Shear seismicity along the ice–bed interface provides a window into these processes. Such seismicity requires a rapid loss of strength that is typically ascribed to rate-weakening friction, i.e., decreasing...
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Cambridge University Press
2019
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ftdoajarticles:oai:doaj.org/article:82430bfcb66740f193b5f4c275d94401 2023-05-15T13:29:35+02:00 Glacier sliding, seismicity and sediment entrainment Bradley Paul Lipovsky Colin R. Meyer Lucas K. Zoet Christine McCarthy Dougal D. Hansen Alan W. Rempel Florent Gimbert 2019-09-01T00:00:00Z https://doi.org/10.1017/aog.2019.24 https://doaj.org/article/82430bfcb66740f193b5f4c275d94401 EN eng Cambridge University Press https://www.cambridge.org/core/product/identifier/S0260305519000247/type/journal_article https://doaj.org/toc/0260-3055 https://doaj.org/toc/1727-5644 doi:10.1017/aog.2019.24 0260-3055 1727-5644 https://doaj.org/article/82430bfcb66740f193b5f4c275d94401 Annals of Glaciology, Vol 60, Pp 182-192 (2019) glacier mechanics processes and landforms of glacial erosion seismicity seismology subglacial processes Meteorology. Climatology QC851-999 article 2019 ftdoajarticles https://doi.org/10.1017/aog.2019.24 2023-03-12T01:31:55Z The evolution of glaciers and ice sheets depends on processes in the subglacial environment. Shear seismicity along the ice–bed interface provides a window into these processes. Such seismicity requires a rapid loss of strength that is typically ascribed to rate-weakening friction, i.e., decreasing friction with sliding or sliding rate. Many friction experiments have investigated glacial materials at the temperate conditions typical of fast flowing glacier beds. To our knowledge, however, these studies have all found rate-strengthening friction. Here, we investigate the possibility that rate-weakening rock-on-rock friction between sediments frozen to the bottom of the glacier and the underlying water-saturated sediments or bedrock may be responsible for subglacial shear seismicity along temperate glacier beds. We test this ‘entrainment-seismicity hypothesis’ using targeted laboratory experiments and simple models of glacier sliding, seismicity and sediment entrainment. These models suggest that sediment entrainment may be a necessary but not sufficient condition for the occurrence of basal shear seismicity. We propose that stagnation at the Whillans Ice Stream, West Antarctica may be caused by the growth of a frozen fringe of entrained sediment in the ice stream margins. Our results suggest that basal shear seismicity may indicate geomorphic activity. Article in Journal/Newspaper Annals of Glaciology Antarc* Antarctica West Antarctica Whillans Ice Stream Directory of Open Access Journals: DOAJ Articles West Antarctica Whillans ENVELOPE(-64.250,-64.250,-84.450,-84.450) Whillans Ice Stream ENVELOPE(-145.000,-145.000,-83.667,-83.667) Annals of Glaciology 60 79 182 192 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
glacier mechanics processes and landforms of glacial erosion seismicity seismology subglacial processes Meteorology. Climatology QC851-999 |
spellingShingle |
glacier mechanics processes and landforms of glacial erosion seismicity seismology subglacial processes Meteorology. Climatology QC851-999 Bradley Paul Lipovsky Colin R. Meyer Lucas K. Zoet Christine McCarthy Dougal D. Hansen Alan W. Rempel Florent Gimbert Glacier sliding, seismicity and sediment entrainment |
topic_facet |
glacier mechanics processes and landforms of glacial erosion seismicity seismology subglacial processes Meteorology. Climatology QC851-999 |
description |
The evolution of glaciers and ice sheets depends on processes in the subglacial environment. Shear seismicity along the ice–bed interface provides a window into these processes. Such seismicity requires a rapid loss of strength that is typically ascribed to rate-weakening friction, i.e., decreasing friction with sliding or sliding rate. Many friction experiments have investigated glacial materials at the temperate conditions typical of fast flowing glacier beds. To our knowledge, however, these studies have all found rate-strengthening friction. Here, we investigate the possibility that rate-weakening rock-on-rock friction between sediments frozen to the bottom of the glacier and the underlying water-saturated sediments or bedrock may be responsible for subglacial shear seismicity along temperate glacier beds. We test this ‘entrainment-seismicity hypothesis’ using targeted laboratory experiments and simple models of glacier sliding, seismicity and sediment entrainment. These models suggest that sediment entrainment may be a necessary but not sufficient condition for the occurrence of basal shear seismicity. We propose that stagnation at the Whillans Ice Stream, West Antarctica may be caused by the growth of a frozen fringe of entrained sediment in the ice stream margins. Our results suggest that basal shear seismicity may indicate geomorphic activity. |
format |
Article in Journal/Newspaper |
author |
Bradley Paul Lipovsky Colin R. Meyer Lucas K. Zoet Christine McCarthy Dougal D. Hansen Alan W. Rempel Florent Gimbert |
author_facet |
Bradley Paul Lipovsky Colin R. Meyer Lucas K. Zoet Christine McCarthy Dougal D. Hansen Alan W. Rempel Florent Gimbert |
author_sort |
Bradley Paul Lipovsky |
title |
Glacier sliding, seismicity and sediment entrainment |
title_short |
Glacier sliding, seismicity and sediment entrainment |
title_full |
Glacier sliding, seismicity and sediment entrainment |
title_fullStr |
Glacier sliding, seismicity and sediment entrainment |
title_full_unstemmed |
Glacier sliding, seismicity and sediment entrainment |
title_sort |
glacier sliding, seismicity and sediment entrainment |
publisher |
Cambridge University Press |
publishDate |
2019 |
url |
https://doi.org/10.1017/aog.2019.24 https://doaj.org/article/82430bfcb66740f193b5f4c275d94401 |
long_lat |
ENVELOPE(-64.250,-64.250,-84.450,-84.450) ENVELOPE(-145.000,-145.000,-83.667,-83.667) |
geographic |
West Antarctica Whillans Whillans Ice Stream |
geographic_facet |
West Antarctica Whillans Whillans Ice Stream |
genre |
Annals of Glaciology Antarc* Antarctica West Antarctica Whillans Ice Stream |
genre_facet |
Annals of Glaciology Antarc* Antarctica West Antarctica Whillans Ice Stream |
op_source |
Annals of Glaciology, Vol 60, Pp 182-192 (2019) |
op_relation |
https://www.cambridge.org/core/product/identifier/S0260305519000247/type/journal_article https://doaj.org/toc/0260-3055 https://doaj.org/toc/1727-5644 doi:10.1017/aog.2019.24 0260-3055 1727-5644 https://doaj.org/article/82430bfcb66740f193b5f4c275d94401 |
op_doi |
https://doi.org/10.1017/aog.2019.24 |
container_title |
Annals of Glaciology |
container_volume |
60 |
container_issue |
79 |
container_start_page |
182 |
op_container_end_page |
192 |
_version_ |
1766001347741614080 |