| This paper describes the results of CMP reflection processing and refraction tomography processing applied to a seismic profile to delineate a geological structure and a velocity structure across the active Kozu-Matsuda fault. The seismic profile after migration based on CMP reflection processing showed discontinuity and kink of reflectors across the fault. Using the seismic profiles of the Kozu-Matsuda fault, we presumed a southern extension of the fault estimated by Nakata and Imaizumi (2002), and estimated the cumulative vertical offset across the fault at 100 m from throw of a top reflector. On the other hand, refraction tomography processing revealed a shear wave velocity structure around the active fault. The velocity varied from 300 to 1000 m/s and was significantly lower on the west side of the fault. We interpreted the low velocity distribution as being the result of subsidence from reverse faulting. |
