Kinematics of steep bedrock permafrost
The mechanisms that control climate-dependent rockfall from permafrost mountain slopes are currently poorly understood. In this study, we present the results of an extensive rock slope monitoring campaign at the Matterhorn (Switzerland) with a wireless sensor network. A negative dependency of cleft...
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ftunivzuerich:oai:www.zora.uzh.ch:68816 2024-10-20T14:09:21+00:00 Kinematics of steep bedrock permafrost Hasler, Andreas Gruber, Stephan Beutel, Jan 2012 application/pdf https://www.zora.uzh.ch/id/eprint/68816/ https://doi.org/10.1029/2011JF001981 eng eng American Geophysical Union https://www.zora.uzh.ch/id/eprint/68816/1/2012_GruberS_Hasler_2012-JGR_Kopie_.pdf doi:10.5167/uzh-68816 doi:10.1029/2011JF001981 urn:issn:0148-0227 info:eu-repo/semantics/openAccess Hasler, Andreas; Gruber, Stephan; Beutel, Jan (2012). Kinematics of steep bedrock permafrost. Journal of Geophysical Research, 117(F01016):online. Institute of Geography 910 Geography & travel Journal Article PeerReviewed info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion 2012 ftunivzuerich https://doi.org/10.1029/2011JF00198110.5167/uzh-68816 2024-10-09T15:01:16Z The mechanisms that control climate-dependent rockfall from permafrost mountain slopes are currently poorly understood. In this study, we present the results of an extensive rock slope monitoring campaign at the Matterhorn (Switzerland) with a wireless sensor network. A negative dependency of cleft expansion relative to temperature was observed at all clefts for the dominant part of the year. At many clefts this process is interrupted by a period with increased opening and shearing activity in the summer months. More specific, this period lasts from sustained melting within the cleft to the first freezing in autumn. Based on these empirical findings we identify two distinct process regimes governing the cleft motion observed. Combining current theories with laboratory evidence on rock slope movement and stability, we postulate that (1) the negative temperature-dependency is caused by thermomechanical forcing and is reinforced by cryogenic processes during the freezing period and, (2) the enhanced movement in summer originates from a hydro-thermally induced strength reduction in clefts containing perennial ice. It can be assumed that the irreversible part of the process described in (1) slowly modifies the geometric settings and cleft characteristics of permafrost rock slopes in the long term. The thawing related processes (2) can affect stability within hours or weeks. Such short-term stability minima may activate rock masses subject to the slow changes and lead to acceleration and failure. Article in Journal/Newspaper Ice permafrost University of Zurich (UZH): ZORA (Zurich Open Repository and Archive |
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Open Polar |
collection |
University of Zurich (UZH): ZORA (Zurich Open Repository and Archive |
op_collection_id |
ftunivzuerich |
language |
English |
topic |
Institute of Geography 910 Geography & travel |
spellingShingle |
Institute of Geography 910 Geography & travel Hasler, Andreas Gruber, Stephan Beutel, Jan Kinematics of steep bedrock permafrost |
topic_facet |
Institute of Geography 910 Geography & travel |
description |
The mechanisms that control climate-dependent rockfall from permafrost mountain slopes are currently poorly understood. In this study, we present the results of an extensive rock slope monitoring campaign at the Matterhorn (Switzerland) with a wireless sensor network. A negative dependency of cleft expansion relative to temperature was observed at all clefts for the dominant part of the year. At many clefts this process is interrupted by a period with increased opening and shearing activity in the summer months. More specific, this period lasts from sustained melting within the cleft to the first freezing in autumn. Based on these empirical findings we identify two distinct process regimes governing the cleft motion observed. Combining current theories with laboratory evidence on rock slope movement and stability, we postulate that (1) the negative temperature-dependency is caused by thermomechanical forcing and is reinforced by cryogenic processes during the freezing period and, (2) the enhanced movement in summer originates from a hydro-thermally induced strength reduction in clefts containing perennial ice. It can be assumed that the irreversible part of the process described in (1) slowly modifies the geometric settings and cleft characteristics of permafrost rock slopes in the long term. The thawing related processes (2) can affect stability within hours or weeks. Such short-term stability minima may activate rock masses subject to the slow changes and lead to acceleration and failure. |
format |
Article in Journal/Newspaper |
author |
Hasler, Andreas Gruber, Stephan Beutel, Jan |
author_facet |
Hasler, Andreas Gruber, Stephan Beutel, Jan |
author_sort |
Hasler, Andreas |
title |
Kinematics of steep bedrock permafrost |
title_short |
Kinematics of steep bedrock permafrost |
title_full |
Kinematics of steep bedrock permafrost |
title_fullStr |
Kinematics of steep bedrock permafrost |
title_full_unstemmed |
Kinematics of steep bedrock permafrost |
title_sort |
kinematics of steep bedrock permafrost |
publisher |
American Geophysical Union |
publishDate |
2012 |
url |
https://www.zora.uzh.ch/id/eprint/68816/ https://doi.org/10.1029/2011JF001981 |
genre |
Ice permafrost |
genre_facet |
Ice permafrost |
op_source |
Hasler, Andreas; Gruber, Stephan; Beutel, Jan (2012). Kinematics of steep bedrock permafrost. Journal of Geophysical Research, 117(F01016):online. |
op_relation |
https://www.zora.uzh.ch/id/eprint/68816/1/2012_GruberS_Hasler_2012-JGR_Kopie_.pdf doi:10.5167/uzh-68816 doi:10.1029/2011JF001981 urn:issn:0148-0227 |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1029/2011JF00198110.5167/uzh-68816 |
_version_ |
1813448854092120064 |