Abstract We use the template matching method of waveform cross-correlation to pick up the missing earthquakes of the Changqing 4.1 earthquake sequence on February 18, 2020, and construct a high-resolution sequence catalog. Then, we use the spatial distribution of the sequence to quantitatively fit the geometric shape of the seismogenic fault plane, and combine with the focal mechanism solution of the 4.1 earthquake to comprehensively determine the seismogenic structure and possible causes of the Changqing earthquake sequence. The results show that 79 seismic events are identified and located by waveform cross-correlation scanning, which is 1.7 times the original seismic catalog. The dominant strike of the sequence and the focal mechanism solution of the largest earthquake indicate that the seismogenic structure of the sequence is a sinistral strike-slip buried normal fault with a strike of 302° and a dip of 88°. Based on the characteristics of structures and faults near the sequence, it is considered that the occurrence of Changqing 4.1 earthquake sequence may be caused by the heterogeneity of stress field in the tectonic composite position.
LI Xia,WANG Peng,ZHANG Zhihui et al. Detection of Missing Earthquakes and Seismogenic Fault of Changqing 4.1 Earthquake Sequence in Shandong Province[J]. jgg, 2023, 43(12): 1211-1217.
LI Xia,WANG Peng,ZHANG Zhihui et al. Detection of Missing Earthquakes and Seismogenic Fault of Changqing 4.1 Earthquake Sequence in Shandong Province[J]. jgg, 2023, 43(12): 1211-1217.