利用sPL震相测定福建顺昌地区地震震源深度  

Determination of the Focal Depths of Earthquakes in Shunchang, Fujian Using the sPL Phase

作　　者：段刚[1] DUAN Gang(Earthquake Agency of Fujian Province,Fuzhou 350003,Fujian,China)

机构地区：[1]福建省地震局

出　　处：《地震工程学报》2019年第3期745-749,787,共6页China Earthquake Engineering Journal

基　　金：中国地震局监测司“测震台网青年骨干培养专项”(CEA-JC/QNCZ-18141)

摘　　要：选用福建数字地震台网宽频带记录,利用sPL震相测定顺昌地区2007年至2017年间ML≥3.5地震的震源深度。基于地震的震源机制解,结合本地区的速度模型,利用频率-波数法(F-K方法),先计算出相应震中距上不同深度的格林函数,再进一步得到sPL震相在不同深度上的理论波形;根据sPL震相的特点,选用震中距30~50km范围的宽频带台站记录,经过去仪器响应、滤波、旋转至传播路径后,将其和理论波形进行比对,找出波形最为相似的对应深度。结果显示顺昌地区地震深度为7km左右。Based on the broadband records from Fujian Digital Seismic Network, the focal depths of M L≥3.5 earthquakes in Shunchang area, Fujian Province, during 2007-2017 were determined using the sPL phase. Based on the focal mechanism solutions of these earthquakes, combined with the velocity model of the study area, the F-K method was used to calculate the Green's function at different depths in the corresponding epicentral distance;the theoretical waveform of sPL phase at different depths were then obtained. According to the characteristics of the sPL phase, the broadband records of stations within 30-50 km of the epicenter were selected and filtered. They were compared with synthetic seismograms, and the corresponding depth with the most similar waveform was found. The determination results showed that the focal depth was approximately 12 km.

关 键 词：震源机制解 F-K算法 理论地震图 sPL震相 震源深度 

分 类 号：P315.6[天文地球—地震学]