M. Zaré - Assistant Professor, IIEES, Tehran, I.R. Iran,

The south Ghazvin plain has been the location of the great earthquakes during the last 40 years. The Buin-Zahra earthquake of 1 September 1962, Ms=7.2, has devastated the southern Ghazvin plain in the south of Buin-Zahra and Takestan. The Changureh earthquake of 22 June 2002, Mw=6.3 caused a great devastation in the northern Avaj area. These earthquakes caused important damages and life losses of 12225 and 233 killed persons, respectively. The tectonic situation of the region is representative for the presence of important fault lines striking in east-west direction (Ipak fault,North-Tehran fault, Divandarreh-Buin lineament), and the tectonic intersection zones between these trends and the NW-SW trend fault lines (Mosha, Eyvanekey, Soltanieh…).In this paper it is intended to introduce the seismotectonic situation in the prone areas of these two earthquakes and the principal stress directions, using the moment tensor solutions and the quaternary fault systems.