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...
Published in: | Journal of Geophysical Research: Earth Surface |
---|---|
Main Authors: | , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
2012
|
Subjects: | |
Online Access: | https://ir.library.carleton.ca/pub/19143 https://doi.org/10.1029/2011JF001981 |
id |
ftcarletonunivir:oai:carleton.ca:19143 |
---|---|
record_format |
openpolar |
spelling |
ftcarletonunivir:oai:carleton.ca:19143 2023-05-15T16:37:23+02:00 Kinematics of steep bedrock permafrost Hasler, A. (Andreas) Gruber, S. (Stephan) Beutel, J. (Jan) 2012-03-01 https://ir.library.carleton.ca/pub/19143 https://doi.org/10.1029/2011JF001981 en eng https://ir.library.carleton.ca/pub/19143 doi:10.1029/2011JF001981 Journal of Geophysical Research: Earth Surface vol. 117 no. 1 info:eu-repo/semantics/article 2012 ftcarletonunivir https://doi.org/10.1029/2011JF001981 2022-02-06T21:52:02Z 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 o Article in Journal/Newspaper Ice permafrost Carleton University's Institutional Repository Journal of Geophysical Research: Earth Surface 117 F1 n/a n/a |
institution |
Open Polar |
collection |
Carleton University's Institutional Repository |
op_collection_id |
ftcarletonunivir |
language |
English |
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 o |
format |
Article in Journal/Newspaper |
author |
Hasler, A. (Andreas) Gruber, S. (Stephan) Beutel, J. (Jan) |
spellingShingle |
Hasler, A. (Andreas) Gruber, S. (Stephan) Beutel, J. (Jan) Kinematics of steep bedrock permafrost |
author_facet |
Hasler, A. (Andreas) Gruber, S. (Stephan) Beutel, J. (Jan) |
author_sort |
Hasler, A. (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 |
publishDate |
2012 |
url |
https://ir.library.carleton.ca/pub/19143 https://doi.org/10.1029/2011JF001981 |
genre |
Ice permafrost |
genre_facet |
Ice permafrost |
op_source |
Journal of Geophysical Research: Earth Surface vol. 117 no. 1 |
op_relation |
https://ir.library.carleton.ca/pub/19143 doi:10.1029/2011JF001981 |
op_doi |
https://doi.org/10.1029/2011JF001981 |
container_title |
Journal of Geophysical Research: Earth Surface |
container_volume |
117 |
container_issue |
F1 |
container_start_page |
n/a |
op_container_end_page |
n/a |
_version_ |
1766027683574054912 |