AFTERSHOCK DECAY RATES IN THE ZAGROS AND PROBABILISTIC SEISMIC AFTERSHOCK HAZARD ANALYSIS OF THE 2013 APRIL 9 SHONBE (BUSHEHR) EARTHQUAKE

The main goal of this article is to study the Zagros aftershock decay rates. For this propose, the Iranian earthquake catalogue has been collected and homogenized between 2002 to 2014. Eight prominent earthquakes in the Zagros region were selected for aftershock decay rate study. Completeness magnitude and its variation was determined for each event. In order to investigate the behavior of aftershocks in the Zagros seismotectonic province, the Omori law parameters were calculated for selected events. Then, probabilistic aftershock hazard assessment (PAHA) based on aftershock parameters (a, b, P, K) of the 2013 April 9 Shonbe earthquake, has been estimated in temporal duration of 14, 30 and 60 days. In order to evaluate the variation of peak ground acceleration with time in the Zagros region, present attenuation relations and NGA formula has been applied. For calculating the PGA variations with time in 33% probability, we used logic tree for weighing different equation