Effects of fault geometry and subsurface structure model on the strong motion and surface rupture induced by the 2014 kamishiro fault nagano earthquake

The authors used a three-dimensional finite element method (3D-FEM) to examine a series of fault rupture simulations for the 2014 Northern Nagano Earthquake and simultaneously estimate the displacement and strong motions. The computational results confirmed that the maximum responses of ground motions and displacement could be simultaneously evaluated using the appropriate constitutive parameters and fine FEM mesh. However, the duration of the acceleration response and shape of the surface displacement waves were not well simulated. In this study, we examined the influence of the fault bend at a shallow depth and P-and S-wave velocity structure models based on a geological survey. As a result, by taking account of bending of the fault plane and the elastic velocity structure at a shallow depth, it was possible to perform a seismic behaviour analysis using the 3D-FEM approach.