ESTIMATION OF EFFECTIVE STRESS ON ASPERITIES IN INLAND EARTHQUAKES CAUSED BY LARGE STRIKE-SLIP FAULTS AND ITS APPLICATION TO STRONG MOTION SIMULATION

Precise estimation of effective stress on asperities is essential for accurate strong motion prediction, but an estimation method has not been proposed for inland earthquakes caused by large strike-slip faults. Hence, we adopted two different methods to estimate effective stress on asperities. One was an estimation method based on a scaling law by Irikura and Miyake (2001) and on a crack model for evaluating the averaged stress drop. The other was an estimation method based on a model composed of an elastic surface layer (lithosphere) and a viscoelastic basement (asthenosphere) by Fujii and Matsu'ura (2000). We applied the estimates to strong motion simulation, compared the simulated peak ground velocities with those by an empirical attenuation relation by Si and Midorikawa (1999), and finally preferred the latter method.