A probabilistic procedure for scenario-based seismic hazard maps of Greater Tehran

The seismic hazard assessment of Tehran, the capital of Iran with a population of over 10 million, is necessary in the decision-making process for risk reduction. The main objective of this paper is to present a procedure for obtaining maximum hazard maps in seismically active regions such as Tehran with a history of destructive earthquakes, but where the number of the instrumentally recorded large magnitude events is small. The deterministic and probabilistic seismic hazard methods are two quantitative approaches with some practical limitations. To overcome their limitations, the Bayesian statistics are used to estimate maximum earthquake magnitude by combining prior seismological information with the available limited data. The Bayesian approach is used to estimate maximum earthquakes corresponding to different individual ground-motion scenarios at a specific hazard level. The maximum hazard maps are obtained by merging different individual worst-case ground-motion scenarios at a specific hazard level. The hazard analyses under different scenarios are conducted by the finite-fault procedure which uses geological and seismological parameters for each seismic source. The obtained results are in agreement with the observed intensities of historical earthquakes. Moreover, the conventional approach of probabilistic seismic hazard analysis is presented to show the difference between the two procedures. The findings provide information about the seismic design or retrofit of structures and infrastructures. (C) 2017 Elsevier B.V. All rights reserved.