Articles | Volume 22, issue 2
https://doi.org/10.5194/nhess-22-445-2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/nhess-22-445-2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
16 Feb 2022
Research article |
| 16 Feb 2022
| 16 Feb 2022
Multi-method monitoring of rockfall activity along the classic route up Mont Blanc (4809 m a.s.l.) to encourage adaptation by mountaineers
Jacques Mourey
CORRESPONDING AUTHOR
EDYTEM, Savoie Mont-Blanc University, CNRS, 73000 Chambéry,
France
Interdisciplinary Center for Mountain Research, University of
Lausanne, Ch. de l'Institut 18, 1967 Bramois, Switzerland
Pascal Lacroix
ISTerre, IRD-CNRS-OSUG, Grenoble Alpes University, 38400
Saint-Martin-d'Hères, France
Pierre-Allain Duvillard
EDYTEM, Savoie Mont-Blanc University, CNRS, 73000 Chambéry,
France
STYX4D, 73370 Le Bourget du Lac, France
Guilhem Marsy
EDYTEM, Savoie Mont-Blanc University, CNRS, 73000 Chambéry,
France
LISTIC, Savoie Mont-Blanc University, Polytech Annecy-Chambéry,
Annecy-Chambéry, France
TENEVIA, 38240 Meylan, France
Marco Marcer
PACTE, Grenoble Alpes University, Alpine Geography Institute, CNRS,
38041 Grenoble, France
Emmanuel Malet
EDYTEM, Savoie Mont-Blanc University, CNRS, 73000 Chambéry,
France
Ludovic Ravanel
EDYTEM, Savoie Mont-Blanc University, CNRS, 73000 Chambéry,
France
Interdisciplinary Center for Mountain Research, University of
Lausanne, Ch. de l'Institut 18, 1967 Bramois, Switzerland
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Andreas Aspaas, Gregory Bievre, Pascal Lacroix, Nadège Langet, Juditha Aga, Ingrid Skrede, Lene Kristensen, Bernd Etzelmuller, and François Renard
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This preprint is open for discussion and under review for Earth Surface Dynamics (ESurf).
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Climate change increases landslide risk in cold regions. We analyzed 12 years of GPS, borehole, water, and seismic data from two landslides in Arctic Norway, one with permafrost and one without. Both accelerate in spring and autumn due to water infiltration. One slip zone shows increasing snowmelt sensitivity while seismic data reveal seasonal stiffness changes. Results advance understanding of water-driven landslide dynamics in Arctic climates.
Xavier Cailhol, Ludovic Ravanel, and Jacques Mourey
Geogr. Helv., 80, 527–544, https://doi.org/10.5194/gh-80-527-2025, https://doi.org/10.5194/gh-80-527-2025, 2025
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This study examines the impact of climate change on Alpine climbing routes in the western European Alps. By identifying the routes most frequented by French mountain guides across various Alpine massifs, the research combines historical comparisons, contemporary surveys and detailed mapping of geomorphological and glaciological processes.
Juliette Bazin, Ludovic Ravanel, and Sandrine Caroly
EGUsphere, https://doi.org/10.5194/egusphere-2025-5614, https://doi.org/10.5194/egusphere-2025-5614, 2025
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Through a geo-historical study, we compile an inventory of glacial and periglacial events that have prompted risk management actions in the Alps. Analysed through seven guiding principles, this research examines how methods have evolved across Alpine countries. Certain events mark turning points in risk perception. Today, management benefits from improved understanding of both hazards and vulnerabilities.
Ludovic Ravanel, Romain Duphil, Emmanuel Malet, Christine Piot, Olivier Alemany, Xavier Cailhol, and Michel Fauquet
Geogr. Helv., 80, 455–465, https://doi.org/10.5194/gh-80-455-2025, https://doi.org/10.5194/gh-80-455-2025, 2025
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Ice aprons are little-known ice masses on steep Alpine rock faces. They are also paleo-environmental archives as their ice is several thousand years old. A special corer has been developed to sample the ice before analysing it.
Léa Courtial-Manent, Jean-Louis Mugnier, Anta-Clarisse Sarr, Ludovic Ravanel, Julien Carcaillet, Riccardo Vassallo, and Arthur Schwing
Geogr. Helv., 80, 339–362, https://doi.org/10.5194/gh-80-339-2025, https://doi.org/10.5194/gh-80-339-2025, 2025
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This study explores how rocks on glacier surfaces originating from rockfalls help measure erosion rates using a chemical marker called 10Be. By analyzing data from 31 glaciers we found that erosion rates vary widely but can be accurately estimated and reveal links to rock exposure, glacier movement, and climate effects. Comparing 10Be erosion rates to other exhumation rates shows cases of balance, slower erosion, or faster erosion, offering insights into the complex drivers of rockwall erosion.
Matan Ben-Asher, Antoine Chabas, Jean-Yves Josnin, Josué Bock, Emmanuel Malet, Amaël Poulain, Yves Perrette, and Florence Magnin
EGUsphere, https://doi.org/10.5194/egusphere-2025-2450, https://doi.org/10.5194/egusphere-2025-2450, 2025
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We studied how water moves through fractured rock walls in a high mountain area in the Alps. Using sensors and tracers over two years, in a high-altitude site, we tracked where the water came from and when it flowed. Most of it came from melting snow, but some came from rain and older ice. The results show that heat and water flow can speed up the melting of frozen ground, which may affect mountain stability. This helps us understand how climate change influences these fragile environments.
Diego Cusicanqui, Pascal Lacroix, Xavier Bodin, Benjamin Aubrey Robson, Andreas Kääb, and Shelley MacDonell
The Cryosphere, 19, 2559–2581, https://doi.org/10.5194/tc-19-2559-2025, https://doi.org/10.5194/tc-19-2559-2025, 2025
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This study presents a robust methodological approach to detect and analyse rock glacier kinematics using Landsat 7/Landsat 8 imagery. In the semiarid Andes, 382 landforms were monitored, showing an average velocity of 0.37 ± 0.07 m yr⁻¹ over 24 years, with rock glaciers moving 23 % faster. Results demonstrate the feasibility of using medium-resolution optical imagery, combined with radar interferometry, to monitor rock glacier kinematics with widely available satellite datasets.
Benedetta Dini, Pascal Lacroix, and Marie-Pierre Doin
EGUsphere, https://doi.org/10.5194/egusphere-2025-1945, https://doi.org/10.5194/egusphere-2025-1945, 2025
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Landslides can happen without warning. Traditional satellite radar (InSAR) methods help but have limits. Here, we show that lesser-used radar signals can act as early warning markers, when traditional methods fail. Using a landslide in Peru as example, we show signs of instability up to five years before failure. These findings suggest that alternative radar-based approaches can complement existing methods, detecting landslides earlier, with key applicability across large regions.
Andrea Securo, Costanza Del Gobbo, Giovanni Baccolo, Carlo Barbante, Michele Citterio, Fabrizio De Blasi, Marco Marcer, Mauro Valt, and Renato R. Colucci
The Cryosphere, 19, 1335–1352, https://doi.org/10.5194/tc-19-1335-2025, https://doi.org/10.5194/tc-19-1335-2025, 2025
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We have reconstructed the multi-decadal (1980s–2023) ice mass changes for all the current mountain glaciers in the Dolomites. We used historical aerial photographs, drone surveys, and lidar to fill the glaciological data gap for the region. We observed an alarming decline in both glacier area and volume, with some of the glaciers showing smaller losses due to local topography and debris cover feedback. We strongly recommend more specific monitoring of these glaciers.
Feras Abdulsamad, Josué Bock, Florence Magnin, Emmanuel Malet, André Revil, Matan Ben-Asher, Jessy Richard, Pierre-Allain Duvillard, Marios Karaoulis, Thomas Condom, Ludovic Ravanel, and Philip Deline
EGUsphere, https://doi.org/10.5194/egusphere-2025-637, https://doi.org/10.5194/egusphere-2025-637, 2025
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Permafrost dynamics at Aiguille du Midi in the French Alps was investigated using Automated Electrical Resistivity Tomography (A-ERT) during four years. A-ERT reveals seasonal and multi-year permafrost changes. Temperatures estimated using resistivity measurements provide a good agreement with measured temperature in borehole in frozen zone. Variations in active layer thickness across different faces were observed, along with a slight decrease in permafrost resistivity suggesting warming.
Carlo Mologni, Marie Revel, Eric Chaumillon, Emmanuel Malet, Thibault Coulombier, Pierre Sabatier, Pierre Brigode, Gwenael Hervé, Anne-Lise Develle, Laure Schenini, Medhi Messous, Gourguen Davtian, Alain Carré, Delphine Bosch, Natacha Volto, Clément Ménard, Lamya Khalidi, and Fabien Arnaud
Clim. Past, 20, 1837–1860, https://doi.org/10.5194/cp-20-1837-2024, https://doi.org/10.5194/cp-20-1837-2024, 2024
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The reactivity of local to regional hydrosystems to global changes remains understated in East African climate models. By reconstructing a chronicle of seasonal floods and droughts from a lacustrine sedimentary core, this paper highlights the impact of El Niño anomalies in the Awash River valley (Ethiopia). Studying regional hydrosystem feedbacks to global atmospheric anomalies is essential for better comprehending and mitigating the effects of global warming in extreme environments.
Marco Marcer, Pierre-Allain Duvillard, Soňa Tomaškovičová, Steffen Ringsø Nielsen, André Revil, and Thomas Ingeman-Nielsen
The Cryosphere, 18, 1753–1771, https://doi.org/10.5194/tc-18-1753-2024, https://doi.org/10.5194/tc-18-1753-2024, 2024
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This study models present and future rock wall temperatures in the mountains near Sisimiut, creating knowledge on mountain permafrost in Greenland for the first time. Bedrock is mostly frozen but also has temperatures near 0 oC, making it very sensitive to climate changes. Future climatic scenarios indicate a reduction in frozen rock wall areas. Since mountain permafrost thaw is linked to an increase in landslides, these results call for more efforts addressing mountain permafrost in Greenland.
Matan Ben-Asher, Florence Magnin, Sebastian Westermann, Josué Bock, Emmanuel Malet, Johan Berthet, Ludovic Ravanel, and Philip Deline
Earth Surf. Dynam., 11, 899–915, https://doi.org/10.5194/esurf-11-899-2023, https://doi.org/10.5194/esurf-11-899-2023, 2023
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Quantitative knowledge of water availability on high mountain rock slopes is very limited. We use a numerical model and field measurements to estimate the water balance at a steep rock wall site. We show that snowmelt is the main source of water at elevations >3600 m and that snowpack hydrology and sublimation are key factors. The new information presented here can be used to improve the understanding of thermal, hydrogeological, and mechanical processes on steep mountain rock slopes.
Suvrat Kaushik, Ludovic Ravanel, Florence Magnin, Yajing Yan, Emmanuel Trouve, and Diego Cusicanqui
The Cryosphere, 16, 4251–4271, https://doi.org/10.5194/tc-16-4251-2022, https://doi.org/10.5194/tc-16-4251-2022, 2022
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Climate change impacts all parts of the cryosphere but most importantly the smaller ice bodies like ice aprons (IAs). This study is the first attempt on a regional scale to assess the impacts of the changing climate on these small but very important ice bodies. Our study shows that IAs have consistently lost mass over the past decades. The effects of climate variables, particularly temperature and precipitation and topographic factors, were analysed on the loss of IA area.
S. Kaushik, S. Leinss, L. Ravanel, E. Trouvé, Y. Yan, and F. Magnin
ISPRS Ann. Photogramm. Remote Sens. Spatial Inf. Sci., V-3-2022, 325–332, https://doi.org/10.5194/isprs-annals-V-3-2022-325-2022, https://doi.org/10.5194/isprs-annals-V-3-2022-325-2022, 2022
Bernd Etzelmüller, Justyna Czekirda, Florence Magnin, Pierre-Allain Duvillard, Ludovic Ravanel, Emanuelle Malet, Andreas Aspaas, Lene Kristensen, Ingrid Skrede, Gudrun D. Majala, Benjamin Jacobs, Johannes Leinauer, Christian Hauck, Christin Hilbich, Martina Böhme, Reginald Hermanns, Harald Ø. Eriksen, Tom Rune Lauknes, Michael Krautblatter, and Sebastian Westermann
Earth Surf. Dynam., 10, 97–129, https://doi.org/10.5194/esurf-10-97-2022, https://doi.org/10.5194/esurf-10-97-2022, 2022
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This paper is a multi-authored study documenting the possible existence of permafrost in permanently monitored rockslides in Norway for the first time by combining a multitude of field data, including geophysical surveys in rock walls. The paper discusses the possible role of thermal regime and rockslide movement, and it evaluates the possible impact of atmospheric warming on rockslide dynamics in Norwegian mountains.
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Short summary
More frequent rockfalls in high alpine environments due to climate change are a growing threat to mountaineers. This hazard is particularly important on the classic route up Mont Blanc. Our results show that rockfalls are most frequent during snowmelt periods and the warmest hours of the day, and that mountaineers do not adapt to the local rockfall hazard when planning their ascent. Disseminating the knowledge acquired from our study caused management measures to be implemented for the route.
More frequent rockfalls in high alpine environments due to climate change are a growing threat...
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