Acknowledgements
This work has been supported by the China Postdoctoral Science
Foundation (2019M650317) and the National Natural Science Foundation of
China (Grants 41904043; U1939202). Waveforms are downloaded from the
data management centers of the Incorporated Research Institutions for
Seismology (IRIS, http://www.iris.edu) and the China National Seismic
Network at Institute of Geophysics, China Earthquake Administration
(SEISDMC, doi:10.11998/SeisDmc/SN). Figures are produced by the Generic
Mapping Tools of Wessel and Smith (2013). We thank Professor Jian Wang
at the Institute of Geology and Geophysics, Chinese Academy of Sciences
for help in using PickNet. The authors acknowledge the course ‘English
Presentation for Geophysical Research of Peking University (Course
#01201110) for help in improving the manuscript.