2022 年 22 巻 6 号 p. 6_1-6_21
At regional scales, modeling the subsurface structure for physics-based numerical simulations poses a challenge, hence two of the most common modeling techniques are juxtaposed in this study. Simulations from both models are carried out using a seismic modeling code SW4 for two aftershocks of the 2007 Niigata Chuetsu-Oki earthquake and validated against recorded data from Kashiwazaki-Kariwa Nuclear Power Plant and three K-NET stations in the form of waveforms, response spectra, amplification factors and goodness-of-fit, which highlight the importance of geotechnical layers in capturing the site-specific response. Regional attenuation of ground motions from the two subsurface models is compared with recorded peak ground accelerations in the region and NGA-West2 ground motion prediction equations, revealing the realistic scattering pattern that can only be replicated by acknowledging a 3D subsurface structure. In conclusion, both the models have their individual merits and limitations that are reported after extensive qualitative and quantitative validations.
