GMSS2.0: An Enhanced Software Program for Stochastic Finite-Fault Ground-Motion Simulation

Abstract

This article introduces an enhanced software program for stochastic ground-motion simulations using finite-fault sources, named Ground-Motion Simulation System version 2.0 (GMSS2.0). GMSS2.0 embodies an updated theoretical model of corner frequency and source duration, making the seismological model for defining the Fourier amplitude spectrum for each subfault more theoretically consistent. In addition, GMSS2.0 provides four rupture scaling relationships and five baseline correction techniques for end users to select the most suitable one for a specific application. For validation purposes, comprehensive comparisons between GMSS2.0 and EXtended SIMulation (EXSIM) for wide ranges of magnitude (M 4–8), distance (∼6–300 km) and spectral period (0.01–10 s) have been performed. The results show that GMSS2.0 can give remarkably close estimates to EXSIM with reasonable levels of accuracy. Finally, further validation is performed by comparing GMSS2.0 simulations with five Next Generation Attenuation-West2 ground-motion models for multiple scenario earthquakes with the updated site amplification for the generic California condition (VS30=500 m/s).