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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.




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...

Erforschung Lawinendynamik

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...

Abseits der Piste

Avalanche science and prevention

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


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...


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.



Rupperslaui, January 2017

Detailed description of the weather, snowpack and avalanche danger during the preceding hydrological year (October 2016 to September 2017).

This wet slab avalanche (outlined in red) swept away two climbers as they were descending the Zinalrothorn on June 19, 2014. They plunged several hundred metres down a rock face and were dead when rescuers arrived. (Photo: B. Jelk)

Even in summer, avalanches pose a threat in some parts of the Swiss Alps. To prevent accidents, a few rules should be followed in the mountains.

During its General Assembly, the EAWS defined guidelines governing votes and elections. Photo: EAWS

The avalanche warning services operating in Europe have undertaken to develop common standards for their activities. Their General Assembly recently...

Starting zone of the ice avalanche in the Tibetan Plateau. Photo: Wentao Hu

A Chinese researcher is currently working at the SLF for a month. Using simulation software developed by SLF, he is learning how to improve...