Seismic hazard in Switzerland

Seismic hazard in Switzerland is classified as moderate. This means that strong earthquakes may occur in Switzerland, but considerably less frequently than in highly threatened areas, such as in Turkey. There is a greater hazard level in the Valais, in the Basel Region, in Central Switzerland, in the Engadin and in the upper Rhine Valley.

Seismic risk in Switzerland

In Switzerland, an earthquake of magnitude 6 on the Richter scale and causing damage on a regional scale may be expected every 100 years or so. A supraregional destructive earthquake of magnitude 7 may be expected every 1,000 years. Due to the density of the population and the high value of the material assets, earthquakes carry the greatest damage potential due to natural hazards in Switzerland. Regarded over the long-term, the seismic risk in Switzerland is comparable with the risk related to flooding: floods are far more frequent but their consequences are less serious.

Need for action and responsibilities

The Confederation implements preventive measures in its own domain of competence, that is for buildings and infrastructure systems that are propriety of the Confederation or requiring federal approval as well as federal financing. In all other domains, the cantons, communes and above all private persons and institutions are responsible for the implementation of preventive measures. The key factors in the proper implementation of these measures are the explicit requirements in the cantonal building legislations, a lasting awareness raising for building owners, the appropriate expertise among project planners, and targeted controls to ensure compliance with earthquake regulations in the building permit procedures. With its programm of measures, the Confederation undetakes its part as a role model and tries to promote earthquake mitigation by supporting other stakeholders with methodological bases and expertise.

Further information is available in German and French.