Numerical 2D modeling of site responsein Dinar Graben, Southwest Turkey,and comparison with observations

The October 1, 1995 Dinar earthquake (ML=5.9) caused extensive damage within a limited area in Dinar town located
in southwestern Turkey. Graben structure of the damaged area suggests the basin edge effects as a potential
factor on the occurred damage. In this study numerical 2D site responses in the Dinar Graben are computed by
using a finite-difference scheme and numerical results are compared with the observations within the graben. Our
results suggest that the ground motions within the Dinar Graben were dominated by surface waves generated from
the edges of the garben. In addition to magnifying amplitudes within the graben, the surface waves increased the
duration of ground motion. Synthetic response spectra of the mainshock have shown that spectral accelerations at
different sites in the graben are larger than the observed one. High spectral accelerations and long durations of
ground motion may explain the extensive damage observed within the Dinar Graben.