Modelling Transient Ground Surface Temperatures of Past Rockfall Events: Towards a Better Understanding of Failure Mechanisms in Changing Periglacial Environments

Despite the rising interest in mountain permafrost due to climatic changes and a noticed increase of registered rockfall events in the European Alps and other mountain ranges, little is known about transient thermal conditions in the detachment areas of rockfalls. Temperature conditions prior to the rockfall events of 144 past events in the European Alps were modelled with a physically based ground temperature model. To minimise the impact that uncertainty has on interpretations, only relative values were used, that is, percentiles obtained from cumulative distribution functions of the modelled ground surface temperatures from the beginning of the meteorological measurement series up to the event dates. Our results suggest that small and mid-sized rockfalls (volumes up to 100 000 m3) from high elevation occurred mainly during short-term periods of unusually high temperatures. This was neither found to be a result of the seasonal distribution (most analysed events in higher elevations occurred from July to September) nor of the longer-term temporal distribution (most analysed events occurred after 2000) only. Plausible explanations are either a destabilisation related to advective thaw or failure due to stress redistribution caused by large temperature variations. Large deep-seated rock slope failures (≥100 000 m3) in high elevation occurred all year round

Sidewall erosion: Insights from in situ ‐produced 10 Be concentrations measured on supraglacial clasts (Mont Blanc massif, France)

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Ice thawing, mountains falling - are alpine rock slope failures increasing?

Many high-mountain environments of the world have seen dramatic changes in the past years and decades. Glaciers are retreating and downwasting, often at a dramatically fast pace, leaving large amounts of potentially unstable debris, moraines and rock slopes behind. Although in the main invisible to the eye of an observer, permafrost, i.e. rock and debris with permanent zero or subzero temperatures, is thawing. Several slopes have become unstable and landslides potentially related to permafrost degradation have received wide-ranging attention from both scientists and the media. A number of those landslides can be related to the effects of recent changes in the cryosphere, which are ultimately driven by changes in climatic parameters, in particular temperature and precipitation

Rock falls in the Mont Blanc Massif in 2007 and 2008

Due to a lack of systematic observations, the intensity and volume of rock falls and rock avalanches in high mountain areas are still poorly known. Nevertheless, these phenomena could have burly consequences. To document present rock falls, a network of observers (guides, mountaineers, and hut wardens) was initiated in the Mont Blanc Massif in 2005 and became fully operational in 2007. This article presents data on the 66 rock falls (100 m3 ≤ V ≤ 50,000 m3) documented in 2007 (n = 41) and 2008 (n = 25). Most o

17 years of high-altitude rock wall monitoring by terrestrial laser scanning (Mont-Blanc massif)

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Analysis of potentially hazardous rockglaciers in Aosta Valley (Italy): the Pointe d'Arpisson destabilized rockglacier

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Permafrost temperature regimes in boreholes in the French Alps - three years of monitoring 2009-2012

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Study of petroglyphs at the Russian Altai in 2015

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