Multi-method monitoring of rockfall activity along the classic route up Mont Blanc (4809 m a.s.l.) to encourage adaptation by mountaineers

There are on average 35 fatal mountaineering accidents per summer in France. On average, since 1990, 3.7 of them have occurred every summer in the Grand Couloir du Goûter, on the classic route up Mont Blanc (4809 m a.s.l.). Rockfall is one of the main factors that explain this high accident rate and...

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Published in:Natural Hazards and Earth System Sciences
Main Authors: J. Mourey, P. Lacroix, P.-A. Duvillard, G. Marsy, M. Marcer, E. Malet, L. Ravanel
Format: Article in Journal/Newspaper
Language:English
Published: Copernicus Publications 2022
Subjects:
G
Online Access:https://doi.org/10.5194/nhess-22-445-2022
https://doaj.org/article/a131929bf9ba449386e2b8289a13b10c
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spelling ftdoajarticles:oai:doaj.org/article:a131929bf9ba449386e2b8289a13b10c 2023-05-15T17:58:21+02:00 Multi-method monitoring of rockfall activity along the classic route up Mont Blanc (4809 m a.s.l.) to encourage adaptation by mountaineers J. Mourey P. Lacroix P.-A. Duvillard G. Marsy M. Marcer E. Malet L. Ravanel 2022-02-01T00:00:00Z https://doi.org/10.5194/nhess-22-445-2022 https://doaj.org/article/a131929bf9ba449386e2b8289a13b10c EN eng Copernicus Publications https://nhess.copernicus.org/articles/22/445/2022/nhess-22-445-2022.pdf https://doaj.org/toc/1561-8633 https://doaj.org/toc/1684-9981 doi:10.5194/nhess-22-445-2022 1561-8633 1684-9981 https://doaj.org/article/a131929bf9ba449386e2b8289a13b10c Natural Hazards and Earth System Sciences, Vol 22, Pp 445-460 (2022) Environmental technology. Sanitary engineering TD1-1066 Geography. Anthropology. Recreation G Environmental sciences GE1-350 Geology QE1-996.5 article 2022 ftdoajarticles https://doi.org/10.5194/nhess-22-445-2022 2022-12-31T15:59:53Z There are on average 35 fatal mountaineering accidents per summer in France. On average, since 1990, 3.7 of them have occurred every summer in the Grand Couloir du Goûter, on the classic route up Mont Blanc (4809 m a.s.l.). Rockfall is one of the main factors that explain this high accident rate and contribute to making it one of the most accident-prone areas in the Alps for mountaineers. In this particular context, the objective of this study is to document the rockfall activity and its triggering factors in the Grand Couloir du Goûter in order to disseminate the results to mountaineers and favour their adaptation to the local rockfall hazard. Using a multi-method monitoring system (five seismic sensors, an automatic digital camera, three rock subsurface temperature sensors, a traffic sensor, a high-resolution topographical survey, two weather stations and a rain gauge), we acquired a continuous database on rockfalls during a period of 68 d in 2019 and some of their potential triggering factors (precipitation, ground and air temperatures, snow cover, frequentation by climbers). At the seasonal scale, our results confirm previous studies showing that rockfalls are most frequent during the snowmelt period in permafrost-affected rockwalls. Furthermore, the unprecedented time precision and completeness of our rockfall database at high elevation thanks to seismic sensors allowed us to investigate the factors triggering rockfalls. We found a clear correlation between rockfall frequency and air temperature, with a 2 h delay between peak air temperature and peak rockfall activity. A small number of rockfalls seem to be triggered by mountaineers. Our data set shows that climbers are not aware of the variations in rockfall frequency and/or cannot/will not adapt their behaviour to this hazard. These results should help to define an adaptation strategy for climbers. Therefore, we disseminated our results within the mountaineering community thanks to the full integration of our results into the management of the route by ... Article in Journal/Newspaper permafrost Directory of Open Access Journals: DOAJ Articles Mont Blanc ENVELOPE(69.468,69.468,-49.461,-49.461) Natural Hazards and Earth System Sciences 22 2 445 460
institution Open Polar
collection Directory of Open Access Journals: DOAJ Articles
op_collection_id ftdoajarticles
language English
topic Environmental technology. Sanitary engineering
TD1-1066
Geography. Anthropology. Recreation
G
Environmental sciences
GE1-350
Geology
QE1-996.5
spellingShingle Environmental technology. Sanitary engineering
TD1-1066
Geography. Anthropology. Recreation
G
Environmental sciences
GE1-350
Geology
QE1-996.5
J. Mourey
P. Lacroix
P.-A. Duvillard
G. Marsy
M. Marcer
E. Malet
L. Ravanel
Multi-method monitoring of rockfall activity along the classic route up Mont Blanc (4809 m a.s.l.) to encourage adaptation by mountaineers
topic_facet Environmental technology. Sanitary engineering
TD1-1066
Geography. Anthropology. Recreation
G
Environmental sciences
GE1-350
Geology
QE1-996.5
description There are on average 35 fatal mountaineering accidents per summer in France. On average, since 1990, 3.7 of them have occurred every summer in the Grand Couloir du Goûter, on the classic route up Mont Blanc (4809 m a.s.l.). Rockfall is one of the main factors that explain this high accident rate and contribute to making it one of the most accident-prone areas in the Alps for mountaineers. In this particular context, the objective of this study is to document the rockfall activity and its triggering factors in the Grand Couloir du Goûter in order to disseminate the results to mountaineers and favour their adaptation to the local rockfall hazard. Using a multi-method monitoring system (five seismic sensors, an automatic digital camera, three rock subsurface temperature sensors, a traffic sensor, a high-resolution topographical survey, two weather stations and a rain gauge), we acquired a continuous database on rockfalls during a period of 68 d in 2019 and some of their potential triggering factors (precipitation, ground and air temperatures, snow cover, frequentation by climbers). At the seasonal scale, our results confirm previous studies showing that rockfalls are most frequent during the snowmelt period in permafrost-affected rockwalls. Furthermore, the unprecedented time precision and completeness of our rockfall database at high elevation thanks to seismic sensors allowed us to investigate the factors triggering rockfalls. We found a clear correlation between rockfall frequency and air temperature, with a 2 h delay between peak air temperature and peak rockfall activity. A small number of rockfalls seem to be triggered by mountaineers. Our data set shows that climbers are not aware of the variations in rockfall frequency and/or cannot/will not adapt their behaviour to this hazard. These results should help to define an adaptation strategy for climbers. Therefore, we disseminated our results within the mountaineering community thanks to the full integration of our results into the management of the route by ...
format Article in Journal/Newspaper
author J. Mourey
P. Lacroix
P.-A. Duvillard
G. Marsy
M. Marcer
E. Malet
L. Ravanel
author_facet J. Mourey
P. Lacroix
P.-A. Duvillard
G. Marsy
M. Marcer
E. Malet
L. Ravanel
author_sort J. Mourey
title Multi-method monitoring of rockfall activity along the classic route up Mont Blanc (4809 m a.s.l.) to encourage adaptation by mountaineers
title_short Multi-method monitoring of rockfall activity along the classic route up Mont Blanc (4809 m a.s.l.) to encourage adaptation by mountaineers
title_full Multi-method monitoring of rockfall activity along the classic route up Mont Blanc (4809 m a.s.l.) to encourage adaptation by mountaineers
title_fullStr Multi-method monitoring of rockfall activity along the classic route up Mont Blanc (4809 m a.s.l.) to encourage adaptation by mountaineers
title_full_unstemmed Multi-method monitoring of rockfall activity along the classic route up Mont Blanc (4809 m a.s.l.) to encourage adaptation by mountaineers
title_sort multi-method monitoring of rockfall activity along the classic route up mont blanc (4809 m a.s.l.) to encourage adaptation by mountaineers
publisher Copernicus Publications
publishDate 2022
url https://doi.org/10.5194/nhess-22-445-2022
https://doaj.org/article/a131929bf9ba449386e2b8289a13b10c
long_lat ENVELOPE(69.468,69.468,-49.461,-49.461)
geographic Mont Blanc
geographic_facet Mont Blanc
genre permafrost
genre_facet permafrost
op_source Natural Hazards and Earth System Sciences, Vol 22, Pp 445-460 (2022)
op_relation https://nhess.copernicus.org/articles/22/445/2022/nhess-22-445-2022.pdf
https://doaj.org/toc/1561-8633
https://doaj.org/toc/1684-9981
doi:10.5194/nhess-22-445-2022
1561-8633
1684-9981
https://doaj.org/article/a131929bf9ba449386e2b8289a13b10c
op_doi https://doi.org/10.5194/nhess-22-445-2022
container_title Natural Hazards and Earth System Sciences
container_volume 22
container_issue 2
container_start_page 445
op_container_end_page 460
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