2016 年 16 巻 11 号 p. 11_41-11_61
The pseudo point-source model is one of the source models applied to explain strong ground motions of the 2011 Tohoku earthquake. We have used this model to simulate strong ground motions at strong-motion stations in the Kanto Plain, Japan, and its accuracy was examined primarily based on Fourier spectra. The results indicate that the Fourier spectra were underestimated at many stations by the original path model, in which two factors are neglected: (1) the geometrical spreading term inversely proportional to the square root of the distance at great distances, and (2) the lower bound of the Q value at low frequencies. Using a revised path model that incorporates these factors, good agreement was achieved between the observed and synthetic Fourier spectra in the Kanto Plain.