2021年老挝M_(S)6.0地震序列研究  

Study of the Laos M_(S)6.0 Earthquake Sequence in 2021

作　　者：孙楠[1] 贺素歌[1] 刘自凤 李利波[1] SUN Nan;HE Suge;LIU Zifeng;LI Libo(Yunnan Earthquake Agency,Kunming 650224,Yunnan,China)

机构地区：[1]云南省地震局,云南昆明650224

出　　处：《地震研究》2025年第1期1-9,共9页Journal of Seismological Research

基　　金：云南省重点研发项目(社会发展专项)(202203AC100003);云南省地震科技创新团队(CXTD202405).

摘　　要：云南地震活动与周边强震存在“构造相连,动力同源”的特征,研究周边强震的序列演化特征及发震构造,对云南地区地震研究具有重要意义。2021年12月24日老挝M_(S)6.0地震发生在滇西南地区的NW向整董断裂附近,震源机制解显示,此次地震是一次走滑型破裂事件,破裂方向与区域构造特征一致。老挝M_(S)6.0地震序列属于前震-主震-余震型序列,主震前震中附近出现3~4级地震非常活跃的现象,前震序列参数计算显示b值波动相对幅度较大,h值出现“上翘”形态,而余震序列b值和h值变化均相对平稳,主震的同震库伦应力结果表明老挝地震可能对云南地区有应力加载作用。The seismicity in Yunnan is related with the strong earthquake activities in its surrounding areas because of their“joint structures and homologic driving forces”.So,study of the earthquake evolution and the seismogenic structures in the vicinity will help predict the earthquakes in Yunnan.On November 24,2021,the Laos M_(S)6.0 earthquake occurred near the Zhengdong fault in Southwest Yunnan.Its focal mechanism reveals that the earthquake is a strike-slip fracture event.The rupture extends in consistent with the regional tectonic trend.The Laos M_(S)6.0 earthquake sequence is a typical foreshock-mainshock-aftershock sequence.The foreshock sequence has abundant M_(S)3.0 and M_(S)4.0 earthquakes.According to the parameters of the foreshock sequence,before the main shock the calculated b-value fluctuates with large amplitude,and h-value has an upward trend.On the other hand,in the aftershock sequence,variation of b-value and h-value is relatively stable.In addition,the coseismic Coulomb stress caused by the M_(S)6.0 mainshock may have a stress-loading effect on Yunnan region.

关 键 词：老挝M_(S)6.0地震 前震序列 余震序列 序列参数 

分 类 号：P315.72[天文地球—地震学]