Stochastic finite-fault modeling of Ms 6.8 Luding earthquake in 2022 and seismic hazard scenario of Moxi fault, southwestern China

The development of ground motion models is an essential part of seismic hazard analysis. Based on the stochastic finite-fault method, this study conducted a scenario-based seismic hazard analysis of the Moxi fault. Because of the variability in amplification coefficients caused by the complex terrain, a genetic algorithm based on four previous earthquakes was used to identify site amplification. The simulations of the Ms 6.8 Luding earthquake in 2022 indicated that the correction of site amplification effectively reduced the model deviation and resulted in a close match between the simulated 5%-damped spectral acceleration and the observations. Subsequently, utilizing the calibrated input parameters and a hybrid source model, the ground motion of the Mw 7.1 scenario earthquake was synthesized to reflect uncertainties in the source parameters. To represent the dynamic properties of the structures, effective peak acceleration was used as a ground motion intensity measure. The source model with the synthetic effective peak acceleration closest to the average simulation result from 30 hybrid source models was selected and used to generate a seismic hazard map for the entire area. The prediction of earthquake scenarios provides a basis for earthquake disaster loss evaluation and seismic fortification of engineering structures.