Hazard and Risk

Earthquakes pose the greatest risk of all natural disasters in Switzerland – greater even than flooding and epidemics (KATARISK, 2003: Disasters and Emergencies in Switzerland).

The seismic hazard specifies the probability of an earthquake of a certain magnitude occuring in a certain area and within a certain timeframe. To estimate this seismologists use regional information about earthquake history, tectonics and geology, historical damage reports and models of wave propagation. The production and regular review of seismic hazard reports for Switzerland is one of the core tasks of the SED.

Estimating the seismic hazard is the first step to assessing and containing the seismic risk, which combines the seismic hazard with information about the local subsoil and factors describing the affected assets (population density and space utilisation) and their vulnerability (type and quality of building construction and infrastructure). 

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