The analysis of 2003 Saros earthquake sequence, North Eastern aegean region and a calibration study of surface wawe magnitude (Ms)

Abstract

This study includes works on two different topics. In the first part, we analyzed the aftershock activity following Mw=5.8, 6th July 2003 Saros earthquake. The activity took place along the axis of the Saros gulf between the depths of 8 km and 20 km. The mainshock occurred at a depth of 17.5 km on the continuation of the North Anatolian Fault Zone (NAFZ) in the Gulf of Saros. Focal mechanism of the mainshock and largest aftershocks are almost pure right lateral strike slip with minor normal faulting. Strikes of the fault mechanism solutions are aligned with the axis of Saros depression. in the second part of this study, three different surface wave magnitude (Ms) formulae, Prague, Herak and Herak and Modified Prague formulae were used to determine Ms for earthquakes in and around Turkey between the years 1997 and 2004, recorded at local and regional distances. The results of three Ms formulae with different correction factors were compared. It was concluded that Prague formula and Modified Prague formula produce significantly distance dependent estimates while Herak and Herak formula has no significant distance dependency and more robust Ms values. It was also observed that Herak and Herak formula has better correlation with Moment magnitude than the other two formulae.