RUPTURE PROCESS OF THE 1992 ERZINCAN EARTHQUAKE AND ITS IMPLICATION FOR SEISMOTECTONICS IN EASTERN TURKEY

The 13 March 1992 Erzincan earthquake is different from the previous e arthquakes which have occurred along the North Anatolian fault zone (N AFZ) in that no surface rupture was observed. In order to infer a rupt ure process of this earthquake, we inverted the teleseismic body waves to the source using the method of Kikuchi and Kanamori [1998]. Three different subevents were then distinguished with total seismic moment of M(o) = 1.2 x 10(26) dyn.cm. The major energy release was found to b e during the first subevent with seismic moment of M(o) = 9.4 x 10(25) dyn.cm, rupture length of 30 km, slip amount of 0.7 m and stress drop of 25 bars. The second subevent was right-lateral, as was the case fo r the first one, with a normal faulting component. It was located 10 k m to the southeast from the first one at the intersection of the right -lateral NAFZ with the left-lateral Ovacik fault. The third subevent w ith a right-lateral mechanism was 10 km to the southeast from the seco nd one. These results are in good harmony with regional seismotectonic s in eastern Turkey.