Synthetic Catalogue Simulation in Low-Seismicity Regions and Few Instrumental Records in Central Iran Based on Monte Carlo Method

The region of Naein seismic gap zone in central Iran includes several active faults with high seismicity potential. This shows the necessity of probabilistic seismic hazard analysis (PSHA) in spite of the earthquake records leakage. The aim of this study is to conduct PSHA by generating a synthetic earthquake catalogue based on a small number of real earthquake records in Naein zone. The catalogue was generated by means of Monte Carlo method using the limited real records for the period of 1900 to 2009 AD and their statistical parameters. Afterwards, using aforementioned synthetic data we calculated Guttenberg–Richter relationships (for each active fault as linear seismic sources) and peak ground acceleration (PGA-m/s²) using appropriate attenuation relationships. Then the hazard curves for each of the seismic sources and the total hazard curve were presented. Moreover, annual probability of exceedance and return period of the earthquakes were calculated for the region. Finally, hazard map was presented for return period of 75 and 475 years which show a high level of ground acceleration in the disputed region .