Abstract
In this study, we estimated a three-dimensional structure of deep sedimentary layers around the Tachikawa fault using the receiver function analysis of earthquake records obtained in the K-NET, KiK-net and SK-net. The 63 stations in this area were used in the analysis. We calculated the receiver functions from 20 to 50 ground motion records obtained at each station, and deduced a 1-D subsurface structural model using an inversion based on the simulated annealing method. Then, we constructed a three-dimensional structures of the deep sedimentary layers in this area from integrating the 1-D S-wave velocity profiles at all the stations. The basement depth at hanging-wall side of the Tachikawa fault is larger than that at foot-wall side with a difference of about 1.7km in the 3-D model. Moreover, we calculated ellipticties for fundamental Rayleigh waves using this three dimensional model to compare observed horizontal-to-vertical ratio of earthquake data during the 2011 off the Pacific coast of Tohoku Earthquake. It is indicated that the characteristics of the calculated predominant periods of the ratios show good agreement with the observed ones.
