A Comprehensive Probabilistic Seismic Hazard Analysis of Karaj, Iran Using Classical and Monte Carlo Simulation Approaches

This study provides a comprehensive probabilistic seismic hazard assessment for Karaj, the capital of Alborz province. In the present study, two probabilistic approaches including the classical and Monte Carlo methods are applied. In this regard, the most recent earthquake catalog of the region, as well as, the most appropriate GMPEs based on the statistical tests of the likelihood and the log-likelihood are used. The results indicated that there are differences between the results of two approaches, which is intensified in the longer return periods. This disparity mainly stemmed from the different concept of two methods for incorporating the aleatory uncertainty. In classical PSHA, the aleatory uncertainty takes into account using the integration which is truncated at a fixed number of the logarithmic standard deviation. While, in the Monte Carlo simulation approach, the aleatory uncertainty is considered in calculation using random sampling of GMPEs variability. In addition, the ground motion shaking map of the region for the dominant seismic scenarios including the rupture of the North-Tehran and Eshterhard faults are developed. These seismic scenarios have the potential of producing the greatest acceleration; consequently, the most vulnerability. The outcomes of this study can be used for providing urban plan or estimating the probable economic and casualty losses of Karaj.