SOURCE MODELING OF THE OFF MIYAGI INTRASLAB EARTHQUAKE OF MAY 26, 2003 WITH SPECIAL REFERENCE TO STRONG GROUND MOTIONS IN KITAKAMI BASIN

Abstract

 Some columns of the viaduct of Tohoku Shinkansen in Kitakami Basin, Iwate Prefecture, Japan, suffered shear failure due to the strong ground motions of the 2003 Off Miyagi Intraslab Earthquake while no damage was observed just north of the damaged viaduct. In order to investigate the mechanisms of the difference in damage, a reliable source model should be established to estimate strong ground motions at these sites. In this study, two characterized source models were developed for the earthquake: one is suitable for strong motion simulation in a wide area using frequency-dependent radiation coefficient and the other is optimized for strong motion simulation in Kitakami Basin.