长宁—昭通页岩气示范区小微地震地方性震级测定  

Local magnitude measurement of small-micro earthquakes in the Changning-Zhaotong Shale Gas Demonstration Zone

作　　者：陈颖 田雯[1,2] 吴庆举 姚志祥[1,2] CHEN Ying;TIAN Wen;WU QingJu;YAO ZhiXiang(Institute of Geophysics,China Earthquake Administration,Beijing 100081,China;Key Laboratory of Seismic Observation and Geophysical Imaging,China Earthquake Administration,Beijing 100081,China)

机构地区：[1]中国地震局地球物理研究所,北京100081 [2]中国地震局地震观测与地球物理成像重点实验室,北京100081

出　　处：《地球物理学报》2024年第3期947-959,共13页Chinese Journal of Geophysics

基　　金：国家重点研发计划(2020YFA0710600);中国地震局地球物理研究所基本科研业务费(DQJB22K39)联合资助。

摘　　要：利用长宁—昭通页岩气示范区高密度宽频带流动地震台阵观测资料,基于LOCFLOW流程,获得了2021年4—10月的108727个震级介于-0.1~5.2之间的地震事件精定位目录.鉴于LOCFLOW内置算法测量的震级与中国地震台网中心发布震级之间存在系统偏差,根据里克特震级的定义,分别基于参考震级校正和考虑台基校正的量规函数参数拟合反演两种方法,建立了适用于研究区的地方性震级公式.反演获得的量规函数能够更加准确地反映四川盆地南部研究区小微地震的振幅衰减特征,并获得研究区小微地震更加准确的地方性震级,可应用于页岩气开发区震级-频度关系等与震级相关的研究.Based on the high-density broadband mobile seismic observation array deployed in the Changning-Zhaotong Shale Gas Demonstration Zone, we obtained a precise location catalog of 108727 small-micro earthquakes with magnitudes ranging from -0.1 to 5.2 from April to October 2021 using the LOCFLOW workflow. In view of the systematic deviation between the magnitude measured by the LOCFLOW built-in algorithm and the magnitude published by the China Earthquake Networks Center (CENC), we developed local magnitude formulas suitable for the study area. According to the definition of Richter magnitude, these formulas were derived using two methods: gauge function parameter fitting inversion considering reference magnitude correction and station base correction. These new gauge functions can more accurately represent amplitude attenuation characteristics of small-micro seismic events in the study area in the southern Sichuan Basin. They enable more precise local magnitude assessments for small-micro earthquake events, facilitating research into magnitude-frequency relationships and related studies in shale gas development areas.

关 键 词：地方性震级 诱发地震 参考震级校正 台基校正 

分 类 号：P315[天文地球—地震学]