摘要
应用CAP和深度震相方法,对2018年3月20日发生在广东阳西的M3.7级地震震源深度进行了测定。首先通过CAP方法反演获得震源机制解,拟合最佳震源深度为12km。然后在震中距100km以内的近台识别出清晰的sPL和PmP、sPmP震相,利用频率-波数(F-K)方法,计算出深度震相在不同深度下的理论地震图,与实际观测波形对比测定震源深度为12km。再利用250~400km震中距范围内台站上识别出的sPn与Pn震相的走时差,测得震源深度12.6km。多种方法的研究结果一致,表明该地震震源深度为12km比较可靠。
By using CAP and depth phase method,the focal depth of the M 3.7 earthquake happened on March 20th,2018 in Yangxi of Guangdong Province was determined.Firstly,the focal mechanism solution is inverted by CAP,and the optimal focal depth is got as 12 km.Then the sPL,PmP and sPmP phases are identified clearly at near stations of epicenter distance within 100 km.By using frequency-wavenumber(F-K)method,theoretical seismograms of deep phases at different depths are calculated,and the focal depth is determined as 12 km after compared with the actual observed waveforms.Meanwhile,according to the travel time difference between sPn and Pn phases identified on the stations within the epicenter distance of 250-400 km,the focal depth is measured as 12.6 km.The consistency of the results obtained from several methods indicates that the focal depth of 12 km for this earthquake is a reliable result.
作者
马晓静
吕作勇
姜喜姣
MA Xiaojing;LYU Zuoyong;JIANG Xijiao(Guangdong Earthquake Agency,Guangzhou 510070,China;Key Laboratory of Earthquake Monitoring and Disaster Mitigation Technology,China Earthquake Administration,Guangzhou 510070,China;Key Laboratory of Earthquake Early Warning and Safety Diagnosis of Major Project,Guangzhou 510070,China)
出处
《华南地震》
2019年第2期19-25,共7页
South China Journal of Seismology
基金
中国地震局监测、预报、科研三结合课题(172005)
