The Strong motion simulation technique using site-specific amplification and phase characteristics was originally proposed by Kowada et al. (1998) and its applicability has been extensively studied by the authors (e.g., Nozu and Sugano, 2006). It has been shown that the method can reproduce damaging velocity-pulses generated from shallow crustal earthquakes with high accuracy. The method can also reproduce ground motion velocities from subduction-zone earthquakes in the frequency range from 0.2-1Hz in conjunction with simple characteristic source models. One disadvantage of the method,however, was that it cannot generate a causal ground motion, meaning a ground motion with zero amplitude at the beginning of the time history. In this article, the authors revise the method by introducing a smoothing technique in the procedure to generate Green's functions. It was confirmed that the revised method can generate a causal ground motion, which is in agreement with the observed ground motion during past large earthquakes. The revised method can also account for multiple nonlinear effects (Nozu et al., 2003).
　The computer programs used in this study are available on the attached CD.