Abstract:

The moderate-sized June 27, 1998 Adana earthquake (Mw=6.2) occurred in the Clicia Basin, where a possible extent of the Eastern Anatolian fault is under question. In the present study point-source inversions of the earthquake source are carried out using the teleseismic P and SH waveform in order to determine the source parameters. In the point source modeling stage nearly the same fit is achieved between the observed and the synthetic waveforms for the single and multiple source inversions. Therefore, a single subevent rupture process is considered for the earthquake rupture process. It is also found in the point source modeling trials that the data is requires a deep lower crust rupture with a source location at 24 km depth. The NE-SW trending nodal plane (strike=57o, dip=70o and rake=20o) of the source mechanism is subparallel to the nearby Göksu fault zone and is considered as the fault plane. A seismic moment of 2.24X1018 Nm (Mw=6.2) is calculated for the point source model. As a whole the teleseismic modeling suggests that the earthquake rupture occurred on a branch fault within the GFZ that do not reach the free surface, dips SE and strikes differently from the surface trace of the GFZ.

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