High-Probability Ground Motion Simulation in Maduo County for the Maduo M_(S)7.4 Earthquake in 2021:A Possible Supershear Earthquake  

作　　者：Zongchao Li Zhiwei Ji Jize Sun Hiroe Miyake Yanna Zhao Hongjun Si Mengtan Gao Yi Ding 

机构地区：[1]Institute of Geophysics,China Earthquake Administration,Beijing 100081,China [2]Institute of Earthquake Forecasting,China Earthquake Administration,Beijing 100036,China [3]Shenzhen Academy of Disaster Prevention and Reduction,Shenzhen 518003,China [4]Earthquake Research Institute,The University of Tokyo,Tokyo 113-0032,Japan [5]Geophysical Exploration Center,China Earthquake Administration,Zhengzhou 450003,China [6]Beijing University of Technology,Beijing 100124,China

出　　处：《Journal of Earth Science》2025年第2期781-800,共20页地球科学学刊(英文版)

基　　金：jointly supported by the Youth Fund of the National Natural Science Foundation(No.42104053);the Research Project Fund of the Institute of Geophysics,China Earthquake Administration(No.DQJB22R30);the independent project initiated by the institute of Geophysics,China Earthquake Administration(No.JY2022Z41)。

摘　　要：On May 22,2021,an M_(S)7.4 earthquake occurred in Maduo County,Qinghai Province,on the western plateau of China.The level of seismic monitoring in this area was inadequate,and incomplete seismic waveforms were obtained from a few broadband seismometers located within 300 km of the epicentre.All waveforms showed“truncation”phenomena.The waveforms of earthquakes can guide ground motion inputs in near-fault areas.This paper uses the empirical Green's function method to consider the uncertainties in source parameters and source rupture processes by synthesizing high-probability,accurate waveforms in Maduo County(MAD station)near the epicentre.The acceleration waveform at the DAW strong-motion station,located 176 km from the epicentre,is first synthesized with the observed waveform of the mainshock.This critical step not only provides a more accurate source and rupture model of the Maduo earthquake but also establishes an essential reference standard.Secondly,the inferred models are rigorously applied to synthesize the acceleration waveform of the MAD station,ensuring that the results maintain a high accuracy and probability.The findings suggest that(1)the simulated acceleration waveform for the MAD station can better characterize the actual ground motion characteristics of the M_(S)7.4 earthquake in Maduo County,with high accuracy and probability in peak ground acceleration(Abbreviated as PGA)ranges of 140–240 and 350–390 cm/s^(2),respectively,and(2)the M_(S)7.4 earthquake did not undergo a complete supershear rupture process.The first asperity located on the east side of the epicentre is most likely to undergo supershear rupture.However,the Maduo earthquake may have been a complete subshear rupture.(3)The fault dislocation model of the three-asperity model better matches the actual source rupture process of the Maduo earthquake.This method can provide relatively accurate acceleration waveforms for regions with limited earthquake monitoring capabilities and assist in analysis of building seismic damage respon

关 键 词：Maduo earthquake small earthquake waveform source parameter uncertainty supershear rupture high probability earthquake engineering 

分 类 号：P315.9[天文地球—地震学]