Structural and thermal controls of rockfall frequency and magnitude within rockwall–talus systems (Swiss Alps)
Abstract Both from a systemic and natural hazard perspective, it is essential to understand the causes and frequency of rockfalls in mountain terrain and to predict the block sizes deposited at specific locations. Commonly, rockfalls are studied either retrospectively, using talus slopes, or directl...
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crwiley:10.1002/esp.4155 2024-09-30T14:36:26+00:00 Structural and thermal controls of rockfall frequency and magnitude within rockwall–talus systems (Swiss Alps) Messenzehl, Karoline Dikau, Richard British Society for Geomorphology 2017 http://dx.doi.org/10.1002/esp.4155 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fesp.4155 https://onlinelibrary.wiley.com/doi/pdf/10.1002/esp.4155 en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Earth Surface Processes and Landforms volume 42, issue 13, page 1963-1981 ISSN 0197-9337 1096-9837 journal-article 2017 crwiley https://doi.org/10.1002/esp.4155 2024-09-03T04:22:42Z Abstract Both from a systemic and natural hazard perspective, it is essential to understand the causes and frequency of rockfalls in mountain terrain and to predict the block sizes deposited at specific locations. Commonly, rockfalls are studied either retrospectively, using talus slopes, or directly by rockwall surveys. Nevertheless, our understanding of rockfall activity, particularly at the lower magnitude spectrum, is still incomplete. Moreover, the explanatory framework is rarely addressed explicitly. In this study, we investigate two rockwall–talus systems in the Swiss Alps to estimate the rockfall frequency–magnitude pattern and their key controls. We present a holistic approach that integrates deductive geotechnical and thermal investigations of the source rockwalls with abductive talus‐based explanations of rockfall volume and frequency. The rockwalls' three‐dimensional (3D) joint pattern indicates that 75% of the blocks may be released as debris fall (< 14 m 3 ) and boulder falls (14–61 m 3 ), which is mirrored in the corresponding talus material. Using two‐year records of near‐surface rockwall temperatures as input for a 1D heat conduction model underlines the destabilizing role of seasonal ice segregation. Deepest frost cracking of 300 cm may occur on the north‐northeast (NNE)‐exposed, snow‐rich rockwall, with peaks at the outermost surface. The synthesis of all data suggests that infrequent, large planar slides (approximately every 250 years) overlain by smaller, more frequent wedge and toppling failures (approximately every 17–50 years) as well as high‐frequency flake‐like clasts (3–6 events/year) characterize the rockfall frequency–magnitude pattern at Hungerli Peak. Here, we argue that small‐size rockfalls need more scientific attention, particularly in discontinuous permafrost zones. Our study emphasizes that future frequency–magnitude research should ideally incorporate site‐specific structural and thermal properties, rather than just focusing on climatic or meteorological triggers. We ... Article in Journal/Newspaper Ice permafrost wedge* Wiley Online Library Boulder Falls ENVELOPE(-107.586,-107.586,67.468,67.468) Earth Surface Processes and Landforms 42 13 1963 1981 |
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Open Polar |
collection |
Wiley Online Library |
op_collection_id |
crwiley |
language |
English |
description |
Abstract Both from a systemic and natural hazard perspective, it is essential to understand the causes and frequency of rockfalls in mountain terrain and to predict the block sizes deposited at specific locations. Commonly, rockfalls are studied either retrospectively, using talus slopes, or directly by rockwall surveys. Nevertheless, our understanding of rockfall activity, particularly at the lower magnitude spectrum, is still incomplete. Moreover, the explanatory framework is rarely addressed explicitly. In this study, we investigate two rockwall–talus systems in the Swiss Alps to estimate the rockfall frequency–magnitude pattern and their key controls. We present a holistic approach that integrates deductive geotechnical and thermal investigations of the source rockwalls with abductive talus‐based explanations of rockfall volume and frequency. The rockwalls' three‐dimensional (3D) joint pattern indicates that 75% of the blocks may be released as debris fall (< 14 m 3 ) and boulder falls (14–61 m 3 ), which is mirrored in the corresponding talus material. Using two‐year records of near‐surface rockwall temperatures as input for a 1D heat conduction model underlines the destabilizing role of seasonal ice segregation. Deepest frost cracking of 300 cm may occur on the north‐northeast (NNE)‐exposed, snow‐rich rockwall, with peaks at the outermost surface. The synthesis of all data suggests that infrequent, large planar slides (approximately every 250 years) overlain by smaller, more frequent wedge and toppling failures (approximately every 17–50 years) as well as high‐frequency flake‐like clasts (3–6 events/year) characterize the rockfall frequency–magnitude pattern at Hungerli Peak. Here, we argue that small‐size rockfalls need more scientific attention, particularly in discontinuous permafrost zones. Our study emphasizes that future frequency–magnitude research should ideally incorporate site‐specific structural and thermal properties, rather than just focusing on climatic or meteorological triggers. We ... |
author2 |
British Society for Geomorphology |
format |
Article in Journal/Newspaper |
author |
Messenzehl, Karoline Dikau, Richard |
spellingShingle |
Messenzehl, Karoline Dikau, Richard Structural and thermal controls of rockfall frequency and magnitude within rockwall–talus systems (Swiss Alps) |
author_facet |
Messenzehl, Karoline Dikau, Richard |
author_sort |
Messenzehl, Karoline |
title |
Structural and thermal controls of rockfall frequency and magnitude within rockwall–talus systems (Swiss Alps) |
title_short |
Structural and thermal controls of rockfall frequency and magnitude within rockwall–talus systems (Swiss Alps) |
title_full |
Structural and thermal controls of rockfall frequency and magnitude within rockwall–talus systems (Swiss Alps) |
title_fullStr |
Structural and thermal controls of rockfall frequency and magnitude within rockwall–talus systems (Swiss Alps) |
title_full_unstemmed |
Structural and thermal controls of rockfall frequency and magnitude within rockwall–talus systems (Swiss Alps) |
title_sort |
structural and thermal controls of rockfall frequency and magnitude within rockwall–talus systems (swiss alps) |
publisher |
Wiley |
publishDate |
2017 |
url |
http://dx.doi.org/10.1002/esp.4155 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fesp.4155 https://onlinelibrary.wiley.com/doi/pdf/10.1002/esp.4155 |
long_lat |
ENVELOPE(-107.586,-107.586,67.468,67.468) |
geographic |
Boulder Falls |
geographic_facet |
Boulder Falls |
genre |
Ice permafrost wedge* |
genre_facet |
Ice permafrost wedge* |
op_source |
Earth Surface Processes and Landforms volume 42, issue 13, page 1963-1981 ISSN 0197-9337 1096-9837 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1002/esp.4155 |
container_title |
Earth Surface Processes and Landforms |
container_volume |
42 |
container_issue |
13 |
container_start_page |
1963 |
op_container_end_page |
1981 |
_version_ |
1811639492205871104 |