Seismic Hazard Estimation Based on Non-Poisson Earthquake Occurrences

Abstract

A non-Poisson earthquake occurrence model for seismic hazard estimation is developed to account for the periodicity and the nonstationarity in seismic activities. The model consists of a renewal process model for major fault systems and a nonstationary Poisson-type model for secondary seismic sources, the latter being dominated by the former. The model is identified on the basis of the historical earthquake data for the Kinki District in the western part of Japan, containing the Kyoto-Osaka-Kobe metropolitan area. A simulation model for seismic hazard estimations (ground acceleration and velocity are dealt with) is then developed by combining the non-Poisson earthquake occurrence model and probabilistic attenuation rules. On the basis of the results of the simulation, the significance of the periodicity and the nonstationarity of seismic activities in assessing the seismic risk is discussed.