Reevaluation of soil velocity structure model gained through microtremor array observation in Fukui Plain

In order to improve correspondences between ground models based on the microtremor array observation in Fukui Plain, models by the H/V survey method and results of the gravity analysis, the microtremor array ground models were reevaluated. The reevaluation was done by the inverse analysis through GA of observed dispersion curves. The representative of the dispersion curves was selected as to be along a theoretical fundamental mode dispersion curve of the H/V ground model. By using the method of selection, a reasonable evaluation became possible compared with the forward method using prior information. The main results are as follows. In one site it was suggested that the depth of the seismic bedrock of the existing model should be greatly decreased. In another site, by assuming the low frequency region of the dispersion curve as the first mode, and the higher region as the fundamental mode respectively, a more appropriate ground model was able to be obtained. It was concluded that the correspondences between the three models were much improved as a whole