Source rupture process of the Kocaeli, Turkey, earthquake of August 17, 1999, obtained by joint inversion of near‐field data and teleseismic data

Abstract

The rupture process of the 1999 Turkey earthquake is examined using both near‐field strong motion data and teleseismic body wave data. The derived source parameters are as follows: (strike, dip, slip) = (268°, 86°, 180°), nearly pure strike‐slip; the seismic moment, Mo = 1.7 × 10 20 Nm (Mw = 7.4); the source duration = 20 sec; the fault length = 70 km; the fault width = 15 km. The rupture process is characterized by an asymmetric bilateral rupture propagation and smooth slip. It consists of two major fault segments, a rupture propagating to the west and a second rupture propagating to the east. The maximum dislocation and the maximum dislocation velocity are 6.3 m and 2.7 m/s, respectively, both found at the former segment. The average dislocation is about 4 m. The extent of the coseismic rupture suggests that a considerable part of the anticipated seismic gap remains unruptured.