VALIDATION OF STRONG MOTION SIMULATION BASED ON THE PSEUDO POINT-SOURCE MODEL WITH THE CENTRAL CHIBA EARTHQUAKE OF JULY 23, 2005 AS AN EXAMPLE

Abstract

 We developed a pseudo point-source model for the July 23, 2005 Central Chiba Earthquake (Mj6.0) and conducted strong motion simulation based on the model. In order to investigate the causes of errors involved in the simulation based on the pseudo point-source model and to improve the model, strong motion simulation is conducted for a much wider area. The result reveals that the averaged radiation coefficient yields as good results as the frequency and distance-dependent radiation coefficient, probably because the target event is a deep-focus event and the target stations do not involve near-source stations. The overestimation to the north of the hypocenter is probably due to a backward directivity effect. And the underestimation at larger distance is improved by using a higher Q value.