Some aspects of seismic hazard assessment when comparing different approaches

Abstract

The Cornell and Gumbel approaches to probabilistic seismic hazard assessment have been applied in northeastern Italy to test the influence of various input parameters. Problems related to earthquake source geometry, seismicity descriptors, and attenuation of two ground-motion parameters of engineering interest (peak ground acceleration and macroseismic intensity) have been analyzed. The results seem to be very sensitive to this last variable (attenuation), while different methodologies can lead to very similar evaluations, if properly applied. Properly applied means that all the input parameters are prepared to satisfy the conditions of the chosen approach. In addition, the seismotectonic knowledge of the study region conditions the choice of approach to be applied.