Permafrost Thaw in European Alps Increases Hazards for Local Communities

News Briefing: 22 March 2023

Multiple research stations in the high mountains of France and Switzerland are observing more frequent and larger rockfalls as permafrost thaw increases every year. Although permafrost is commonly associated with the Arctic, such permanently frozen soil and sediments also are a feature of mountain landscapes. These sometimes fill the cracks between rock faces, gluing steep mountain walls together for hundreds to thousands of years. Rising global temperatures and summer heatwaves are melting alpine permafrost deeper than before, reaching ice that had been continually frozen for millennia. Meltwater pooling in these cracks can trigger rockfalls and collapse massive regions of the rock face, especially if they build up enough pressure to widen the crack. Long-term data from monitoring stations positioned throughout the Alps reveals that deepening summer thaw increases temperatures well beneath mountain surfaces. For example, the massive slopes surrounding Mont Blanc have warmed 1°C per decade since the 1980’s. These field measurements will help produce better models to predict the future behavior of mountain permafrost, to identify high-risk regions vulnerable to sudden rockfalls and avalanches as rising temperatures make them more hazardous.

https://www.bbc.com/future/article/20230322-how-climate-change-is-melting-permafrost-in-the-alps