Abstract

On May 21, 2021, at 21:48 local time, an earthquake with a moment magnitude of 6.1 occurred in Yangbi County, Yunnan Province, China. By using the robust strong ground motion data released by the Yunnan Earthquake Agency, we selected five near-field stations (R < 100 km) and determined model parameters, such as the duration, spectral attenuation, stress drop, and site amplification factors of the 2021 Mw 6.1 Yangbi earthquake in China. These model parameters required for the simulation were fed into a stochastic finite-fault model of the corner frequency associated with a dislocation. The modified stochastic finite-fault method was applied to simulate the acceleration recordings of these five near-fault stations, and the acceleration response spectra and Fourier acceleration spectrum were obtained. Comparative observation results reveal that the key input parameters extracted from a few stations and the revised approach established in the current study can adequately predict the near-fault ground motion at high frequencies of the Yangbi earthquake and can demonstrate the contribution of areas with large slips to radiated energy. The proposed method can provide a basis for postdisaster rescue and seismic building design for this region.