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Avalanches are a fascinating, but above all else, a supremely dangerous phenomenon. Research into avalanche formation, dynamics and protection is therefore a key part of our remit. By issuing avalanche warnings for the Swiss Alps, we perform an important national service.


Nowadays, we have a good understanding of how avalanches form. This enables us to publish reliable avalanche bulletins for the benefit of safety officers in ski resorts and local authorities, as well as backcountry skiers, freeriders and snowshoe hikers.

However, we cannot yet predict in detail exactly why, when and where an avalanche will be triggered. We conduct laboratory and field research into how weak layers are generated in the snowpack, how fractures form and propagate in them and how the snowpack eventually begins to slide – in other words, how avalanches form and release.

Complex physical processes are at work inside an avalanche. To be able to accurately assess the scale and destructiveness of avalanches, we have to understand these processes. We therefore need to be able to see inside avalanches. Our Vallée de la Sionne avalanche test site at Arbaz in the canton of Valais has been operating since 1997. The only facility of its kind in the world, it has technical equipment that allows us to gain just this kind of insight. The data collected helps us, among other things, to develop and improve avalanche simulation programs, which are used by engineers worldwide to assess hazards and design protection measures.

Villages and roads can be protected from avalanches in a variety of ways. Refraining from building in vulnerable areas, preventing avalanche formation by planting forestry or erecting barriers, minimising avalanche impact by means of protective structures such as snow sheds, and artificially triggering avalanches using explosives before too much snow has accumulated are just a few of the possibilities. We investigate how these different approaches work and how they can best be combined, including from an economic and legal perspective.

Last but not least, we also examine avalanche accidents involving snow sports enthusiasts in open terrain, to learn lessons for future prevention.



Das Bild zeigt einen schneebedeckten Hang, in dessen oberem Viertel eine Schneebrettlawine angerissen ist.  Eine Aufstiegsspur durchquert die Gleitfläche und im unberührten Schnee links von der Lawine schlängelt sich eine Abfahrtsspur den Hang hinunter.

Avalanche formation

Whether an avalanche occurs depends to a large extent on the structure of the snowpack. We investigate the processes at work in the formation of an...

Das Bild zeigt einen steilen Hang, den eine grosse Staublawine hinabstürzt.

Avalanche dynamics

To assess avalanche danger accurately, we need to understand what goes on inside an avalanche. This allows us to calculate how far it will travel and...

Eine Gruppe von Skitourengänger legt eine frische Spur durch eine ansonsten unberührte Schneedecke.

Avalanche science and prevention

Most avalanche accidents happen off-piste. Preventive behaviour is required to reduce the avalanche risk to an acceptable level.

Ein Ausschnitt des Lawinenbulletins

Avalanche warning

The SLF is responsible for providing an avalanche warning service on behalf of the Swiss federal government. The avalanche bulletin is compiled and...

Image: Stefan Margreth/ SLF

Avalanche protection

Protecting settlements and transport routes from avalanches is indispensable for life in the Alps. We assist planners and authorities with essential...

Auf einem grossen Lawinenkegel in der Leidbachfurka stehen zwei Rettungshubschrauber.

Destructive avalanches and avalanche accidents

We keep a detailed database of avalanche events. Winter reports and accident analyses are a long-standing part of the SLF’s work.



New centre to explore climate change and natural hazards in the Alpine region.

Which measure against avalanches or rockfall has the best cost-benefit ratio? The SLF has helped to develop calculation tools for this purpose.

Reportage in “The New Yorker” about avalanche research and protection in the US and Switzerland, with insight into the work of SLF researchers.

Description of the weather, snowpack and avalanche danger during the preceding year (October 2018 to September 2019). In German or French.