利用经验格林函数谱比法估计2013年芦山地震序列的应力降  

Estimating stress drop of the 2013 Lushan earthquake sequence based on the empirical Green’s function spectral ratio method

作　　者：范业昊 王宏伟[1,2] 温瑞智[1,2] 任叶飞[1,2] Fan Yehao;Wang Hongwei;Wen Ruizhi;Ren Yefei(Institute of Engineering Mechanics,China Earthquake Administration,Harbin 150080,China;Key Laboratory of Earthquake Engineering and Engineering Vibration of China Earthquake Administration,Harbin 150080,China)

机构地区：[1]中国地震局工程力学研究所,中国哈尔滨150080 [2]中国地震局地震工程与工程振动重点实验室,中国哈尔滨150080

出　　处：《地震学报》2023年第1期98-106,共9页Acta Seismologica Sinica

基　　金：黑龙江省自然科学基金项目(LH2020E021);国家重点研发计划项目(2019YFE0115700);中国地震局地震工程与工程振动实验室重点专项(2021EEEVL0202)共同资助。

摘　　要：本文以芦山地震余震为例,分析了基于强震动观测记录的经验格林函数(EGF)谱比法估计地震的拐角频率和应力降的可行性。首先给出能够可靠估计地震拐角频率和应力降的经验格林函数谱比曲线的质量标准;然后利用其估算出17次ML3.8—5.4芦山强余震的拐角频率;最后,参考其它研究给出的地震矩震级,计算出地震应力降。结果显示,芦山强余震的拐角频率主要介于1.0—2.0 Hz之间,应力降平均值为9.98 MPa,且地震应力降表现出明显的震级相关性。We adopted the 2013 Lushan aftershocks as a typical example,to investigate the feasibility of estimating corner frequency and stress drop by the empirical Green’s function(EGF) spectral ratio method based on the strong motion observation data. Firstly,we suggested the quality standard on the EGF spectral ratio curve to guarantee the reliable estimation of seismic corner frequency and stress drop. The corner frequencies for the 17 Lushan aftershocks with magnitude in the range of 3.8-5.4 were then estimated. Referring to the seismic moment magnitude given by other studies,we further computed the seismic stress drops.The results show that the corner frequency of Lushan strong aftershocks is mainly in the range of 1.0-2.0 Hz,the average stress drop is 9.98 MPa,and seismic stress drop presents obvious dependency on seismic magnitude.

关 键 词：经验格林函数 谱比 芦山地震 应力降 

分 类 号：P315.3[天文地球—地震学]