CHARACTERIZED FAULT MODEL FOR PREDICTION OF STRONG GROUND MOTIONS FROM INTRA-SLAB EARTHQUAKES

Abstract

For precise prediction of strong ground motions from intra-slab earthquakes, we proposed a procedure for determining the parameters of the characterized fault models based on the asperity model. The major parameters were the entire fault area, the seismic moment, the averaged stress drop, the area of the asperities, the stress drop on the asperities, and the short-period level of the acceleration source spectrum. We assumed the seismic moment, the area of the asperities, and the short-period level from the data of the actual intra-slab earthquakes, and evaluated the other three parameters by the three theoretical relations between the major parameters. Based on this assumption, we generated a characterized fault model for the 2003 Miyagi-Ken Oki, Japan, earthquake (M_J 7.1) to simulate strong ground motions. The resultant motions showed pretty good agreements with the actual records and with the empirical attenuation relation of Si and Midorikawa (1999).