Introduction
This supplementary material contains 6 figures (Figure S1 to S6).
Anomaly recording station detection process is demonstrated in Figure
S1. Calculation results of correlation coefficient of abnormal recording
stations for GSN and mainland China seismic network for the repeating
earthquakes are illurstrated in Figure S2, Figure S3, respectively.
Figure S4 to S6 shows the original waveform of potential anomalous
stations, which are utilized to confirm anomalous stations.