Recognition of repeating earthquakes in Hunan area and its application to seismic network location evaluation

Based on 778 earthquakes (2009—2022) and their observation reports recorded by the Hunan Seismic Network, through the analysis of the cross-correlation of the waveforms, 149 repeated earthquake pairs were identified which were recorded at least 3 stations with cross-correlation coefficients no less than 0.8. After obtaining these data, the location errors and phase picking errors of the Hunan Seismic Network were statistically analyzed. The results show that the horizontal location error is around 3.5 km, and the vertical location error is around 3 km. The Pg and Sg phase picking errors are about 0.4 s and 0.7 s, respectively. There is no significant difference in location error in Hunan region, except for the Changde area, where the error is basically within 4 km.