DU Hang,ZHENG Jiangrong,JIANG Haolin,et al.Inversion for the Focal Mechanisms of the 2021 Dafeng Sea M5.0 Earthquake and Tianning M4.2 Earthquake Using FOCMEC and CAP Methods[J].Journal of Disaster Prevention and Mitigation Engineering,2022,42(04):874-880.
DU Hang,ZHENG Jiangrong,JIANG Haolin,et al.Inversion for the Focal Mechanisms of the 2021 Dafeng Sea M5.0 Earthquake and Tianning M4.2 Earthquake Using FOCMEC and CAP Methods[J].Journal of Disaster Prevention and Mitigation Engineering,2022,42(04):874-880. DOI: 10.13409/j.cnki.jdpme.20220221001.
Inversion for the Focal Mechanisms of the 2021 Dafeng Sea M5.0 Earthquake and Tianning M4.2 Earthquake Using FOCMEC and CAP Methods
The FOCMEC and CAP methods were used to invert the focal mechanism solutions of the 2021 Dafeng Sea
M
5.0 earthquake and Tianning
M
4.2 earthquake, respectively. The discrepancy between the outcomes by the two methods was analyzed. It was thus found that there is a subtle discrepancy between the outcomes of the focal mechanism of the
M
5.0 earthquake in Da Feng sea area by the FOCMEC method and the CAP method, in which the CAP method generates a more consistent outcome with other institutes. The FOCMEC method and CAP method are basically consistent in calculating focal mechanism solutions of the Tianning
M
4.2 earthquake. By comparing the epicenter and station location of the two earthquakes, it can be seen that the CAP method does not have high requirements for station distribution, but needs a large earthquake magnitude, a high signal-to-noise ratio of waveform, and a good seismic phase fitting degree. Although the FOCMEC method does not have high requirements for earthquake magnitude, it needs an epicenter well surrounded by stations, a high density of stations near the epicenter, and a clear first P motion.
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