Ground Motion Simulations for the 19 January 2020 Jiashi, China, Earthquake Using Stochastic Finite‐Fault Approach

Abstract

A 6.0-magnitude (M w ) earthquake was reported to have occurred in Jiashi County, Xinjiang at 21:27 on 19 January 2020, Beijing time (13:27 UTC). This study applied a stochastic finite-fault approach based on the dynamic corner frequency (EXSIM) to simulate 23 near-field stations within a distance of 120 km from the epicenter. The stochastic finite-fault approach is the simplest and most effective method for simulating high-frequency ground motions. According to studies and empirical relationships, we estimated a region-specific parameter (κ 0 ) for use in simulations. In this study, two different slip models, namely, random and inverted slip models, were used to explain their influence on the simulation results. For most stations, the simulated seismic characteristics, such as the peak ground acceleration (PGA), pseudo spectral acceleration ,and Fourier acceleration spectrum, are highly compatible with the observed values in the frequency range (f > 1 Hz), indicating that the stochastic finite-fault approach is not highly sensitive to input slip distributions and fault dimensions. The simulation results indicated no significance between the two slip models under high-frequency conditions. Finally, based on the predicted PGA values of 1891 field points selected near the fault, the acceleration field of the Jiashi earthquake is plotted. The results show that the use of the acceleration time history predicted by modified EXSIM is feasible and practical in the high-frequency band above 1 Hz.

Simulation of Ground Motion From Finite‐Fault Modeling Incorporating the Influence of Duration

“…Based on different definitions of energy accumulation time, the following formula can be used to directly fit the path duration of earthquake ground motion (Dang et al., 2022; Ghofrani et al., 2013; Sun et al., 2015; Wang et al., 2022): $$$T=m\cdot R+n$$$ where m and n indicate regression coefficients and R represents epicentral distance.…”

“…Based on different definitions of energy accumulation time, the following formula can be used to directly fit the path duration of earthquake ground motion (Dang et al, 2022;Ghofrani et al, 2013;Sun et al, 2015;Wang et al, 2022):…”