Probabilistic seismic hazard analysis

Summary

Probabilistic seismic hazard analysis is a method to compute how often a given level of ground shaking is expected to be exceeded at a site. It combines a model of the earthquake sources, with their rates and magnitude distributions, and a model of the ground motion they produce. The result is a hazard curve: the annual rate of exceedance as a function of the shaking level. Building codes turn it into design values, such as the shaking with a $10\%$ probability of exceedance in $50$ years. The method was introduced by C. Allin Cornell and is the standard basis of seismic hazard maps.