APPLICATION OF STEPP METHOD FOR ASSESSING THE COMPLETENESS OF INSTRUMENTAL AND PRE-INSTRUMENTAL EARTHQUAKE DATA IN DIFFERENT SEISMIC PROVINCES OF IRAN

Seismic hazard assessments are effected by large uncertainties derived from instrumental and pre-instrumental data. One of a significant source of uncertainties is the incompleteness of historical seismic records. Thus, checking the completeness for different magnitude levels is a paramount step in seismic hazard assessment. In this paper STEPP method has been proposed for checking the completeness of seismic catalogues. For this purpose, different de-clustering methods were tested on composite homogenized catalogue of Iran and then Gardner & Knopoff was selected as a final choice for de-clustering the catalogue. Using the STEPP method, the interval in a magnitude class over which the class is complete was determined. After dividing the seismic data, the magnitude of completeness (Mc), defined as the lowest magnitude above which 100% of all events in a given region are detected, is found by maximum curvature method from the complete part of the catalogue.