Rupture process of the 1992 Erzincan Earthquake and its implication for seismotectonics in eastern Turkey

Abstract

The 13 March 1992 Erzincan earthquake is different from the previous earthquakes which have occured along the North Anatolian fault zone (NAFZ) in that no surface rupture was observed. In order to infer a rupture process of this earthquake, we inverted the teleseismic body waves to the source using the method of Kikuchi and Kanamori [1991]. Three different subevents were then distinguished with total seismic moment of Mo = 1.2 × 1026 dyn·cm. The major energy release was found to be during the first subevent with seismic moment of Mo = 9.4 × 1025 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 for the first one, with a normal faulting component. It was located 10 km to the southeast from the first one at the intersection of the right‐lateral NAFZ with the left‐lateral Ovacik fault. The third subevent with a right‐lateral mechanism was 10 km to the southeast from the second one. These results are in good harmony with regional seismotectonics in eastern Turkey.