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Permanently frozen ground or permafrost covers around 6% of the Swiss Alps and occurs primarily above 2400 m. Permafrost can consist of all kinds of frozen ground (rock, scree slopes, moraines etc.). In the summer, only the top layer, called the active layer, thaws. Although not immediately recognisable, permafrost can be made evident by the presence of various terrain features.

Permafrost Bohrloch


Since 1996, boreholes have been drilled and fitted with measurement instruments in more than twenty permafrost locations in the Swiss Alps. The SLF permafrost measurement network supplies essential data on the state of the permafrost and aids the understanding of the complex interaction between the ground surface and underlying substrates. >> more

Verbauung im Permafrost

Building on permafrost

Higher temperatures reduce the load bearing capacity of the foundation soil, enhance soil creep, and induce active layer deepening. In the interests of technical safety, the SLF tests new building methods in mountain permafrost, and issues practical recommendations. >>more


Permafrost and natural hazards

Permafrost is not a natural hazard. When permafrost melts as a consequence of climatic changes, however, the ground becomes less stable, and landslides, scree or soil creep, debris flows and rockfalls can occur. >> more