Hazard-Consistent Magnitude and Distance in Iran

Abstract

This study deals with the deaggregation of probabilistic seismic hazard of Iran. To this, the relative contributions of earthquake parameters to the total hazard are computed by probabilistic seismic hazard analysis (PSHA) deaggregation. Afterwards, the representative values of earthquake magnitude and distance are obtained for all meshes of Iran and they are plotted as hazard-consistent magnitude and distance, respectively. In the deaggregation analysis for major cities with over one million populations, the values of the strong-motion parameter are recalculated using representative values of magnitude and distance of high contributed seismic sources for PGA, PGV and in each period. New seismic parameters will be matching closely with the distance and magnitude values as obtained by the PSHA approach. Probabilistic seismic hazard analysis is a technique for estimation of seismic hazard at a site under the known seismic sources. The relative contributions of the various sources to the total seismic hazard are determined as a function of their occurrence rates and their ground-motion potential. As probabilistic seismic hazard analysis is known as realistic and comprehensive method, it is useful to display the relative contributions to the hazard from the different values of the hazard components, like magnitude and distance of the seismic source to site. The results, which are obtained separately for each seismic source and combined for all the seismic sources in the region, are called the deaggregation of the probabilistic hazard analysis as shown by Bazzurro and Cornell 1) . In this study, the results of probabilistic seismic hazard analysis, which had been done previously by covering all Iran, is used for the deaggregation analysis. Some aspects of deaggregation of seismic hazard for Iran are studied considering the seismic design.