SEGJ Technical Conference

2D S-wave velocity structure estimation based on waveform inversion using cross-correlation function evaluated by seismic interferometry - Application to Ojiya City, Niigata Prefecture -

Abstract Strong ground motions with amplitudes exceeding maximum accelerations of 1G were recorded in Ojiya City in the Mid Niigata Prefecture Earthquake in 2004 (Mj6.8). Yamanaka et al. (2005) have indicated that characteristics of the motions were locally different due to site amplification factors. We applied our waveform inversion technique for retrieving a 2D S-wave velocity profile to the area using cross-correlation functions evaluated by the seismic interferometry analyses. We found that the distribution of the top of a layer with an S-wave velocity of 0.6 km/s is significantly complicated and the observatories for the strong motions were located where a layer having an S-wave velocity of 0.35 km/s is locally distributed.