Numerical Modeling of the 2016 Kumamoto Earthquake: 3D Seismic Wave Propagation Constrained by an Asperity Model

Utilizing an asperity model, this research thoroughly simulates 3D seismic wave propagation to assess the 2016 Kumamoto earthquake. The research employs finite difference methods (FDM) to solve the 3D wave propagation equations incorporating realistic subsurface geological data and slip distributions from the Kumamoto active fault system. The simulation domain covers a 15 km × 12 km subsection of the fault plane, discretized into 250 m³ grid cells, resulting in a 48 × 60 mesh for numerical computation. The model utilized 800 iterative cycles to generate complete ground velocity time histories for an 8 second duration at numerous receiver locations. The results show that the x-direction component has the highest amplitude at station KMMH16, with seismic activity beginning around 3.5 seconds and rising around 5.9 seconds. The timing and intensity of the shaking differed greatly from one location to another primarily based on how far each site was from the fault and the direction in which it was located. This study advances our knowledge of earthquake source mechanics and helps to improve seismic hazard assessment and mitigation techniques by offering crucial insights into the intricacies of seismic wave propagation across heterogeneous media. The study clarifies the complex process of seismic waves propagating across various mediums which advances our knowledge of earthquake dynamics and enhances seismic risk assessment and mitigation strategies.