A declustered earthquake catalog for the Iranian Plateau

Abstract

A unified catalog of earthquakes in Iran and adjacent regions (the area bounded in 22^º-42^ºN and 42^º-66^ºE) covering the period of 4^th century B.C. through 2012 with M_w≥4 is provided. The catalog includes all events for which magnitude have been determined by international agencies and most reliable individual sources. Since the recurrence time of maximum credible earthquake cannot be directly estimated from the m_b, empirical formulae are established to convert m_b to M_s, m_b to M_w and M_s to M_w for each major seismotectonic province separately. The unified catalog is declustered using conjugated distance-time windows. In order to estimate completeness thresholds, magnitude-time (M-T) diagram and Stepp’s method are applied on the declustered catalog for each seismotectonic province. The magnitude of completeness (M_c) decreases with development of local and regional seismic stations. The results of present study are particularly important in seismic hazard analysis in Iran.