Abstract By limiting the diameter of the earthquake swarm concentration area, and deducing the same ray path of two earthquakes at similar distances recorded by a single seismic station, using the method of double difference wave velocity ratio, we carry out characteristic analysis of the wave velocity ratio of the two earthquake swarms in Changdao area from 2017 to 2018. Through the sensitivity analysis of seismic phase data, we conclude that the method of double-difference wave velocity ratio is comparatively sensitive to the noise in arrival time, especially for Pg-wave. The phase errors of Pg-wave and Sg-wave should be controlled within 0.02 to 0.20 s. The final analysis results show that the wave velocity ratio of Changdao earthquake swarm fluctuates in the range of 1.69-1.78, and the change of wave velocity ratio is closely related to the activity process of earthquake swarm. Before the occurrence of several large aftershocks, the wave velocity ratio showed a low state. The wave velocity ratio between main shock and aftershock varies, which may reflect differing seismogenic mechanisms.
ZHAO Rui,ZHENG Jianchang,CUI Huawei et al. Analysis on Features of 2017-2018 Changdao Earthquake Swarms Based on the Wave Velocity Ratio Using a Double-Difference Method[J]. jgg, 2022, 42(11): 1149-1155.
ZHAO Rui,ZHENG Jianchang,CUI Huawei et al. Analysis on Features of 2017-2018 Changdao Earthquake Swarms Based on the Wave Velocity Ratio Using a Double-Difference Method[J]. jgg, 2022, 42(11): 1149-1155.
