Switzerland launches new seismic risk model

An online map from January 2020 showing earthquakes over the previous 90 days that affected Switzerland. © Keystone / Christian Beutler

The cities of Basel, Geneva, Zurich, Lucerne and Bern are at the highest risk of earthquakes in Switzerland, according to the first-ever national seismic risk model launched by the Swiss Seismological Service.

According to the detailed new risk model presentedExternal link on Tuesday, the worst damage to buildings would occur in cantons Bern, Valais, Zurich, Vaud and Basel-​City. The cities of Basel, Geneva, Zurich, Lucerne and Bern are at the highest risk, in that order, it calculates.

“The earthquake hazard differs in these regions, but due to the size of these five cities many people and assets would be affected by an earthquake. These cities also have numerous vulnerable buildings – in some cases highly vulnerable – built on a soft substrate, which intensifies seismic waves,” saidExternal link the Swiss Seismological Service, which is based at the federal technology institute ETH Zurich.

+ How the Swiss Seismological Service tries to predict earthquakes in real time

Based on their model calculations, the experts predict that destructive earthquakes in Switzerland over the next 100 years could cause economic damage of CHF11-44 billion ($11.7- 47.1 billion) to buildings and their contents alone.

Altogether, some 150 to 1,600 people could die, with approximately 40,000 to 175,000 made homeless.

The model was created by the service, together with the Federal Office for the Environment and the Federal Office for Civil Protection, on behalf of the government.

The seismologists combined information about earthquake risk, effects of the local substrate, building vulnerability, and affected persons and assets. The new model complements the hazard map published by the service several years ago.

+ Around 900 earthquakes noted in Switzerland in 2022

Over two quakes a day on average were recorded in or around the Alpine country last year, the Swiss Seismological Service said in February. There was no damage.

The last time minor disruption was recorded was in 1991, after a 5.0-magnitude earthquake in Vaz in canton Graubünden. Further back again, more severe quakes are not unheard of: in 1356, a tremor with a magnitude of 6.6 destroyed the city of Basel.

The largest earthquakes since modern measurement methods were introduced in the region were noted in Annecy in France in 1996 and Bormio in northern Italy in 1999, each with a magnitude of 5.1.