Earth resistivity anomalies at Nantong Seismic Center Station

Ground resistivity is an earthquake prediction method that is influenced by various factors such as rainfall, changes in the environment surrounding the observation station, and observation system failures. Some forms of interference with seismic monitoring data are easily confused with seismic precursors. A ZD8BI digital geoelectric instrument in the NS and EW channel directions is used to determine the ground resistivity at the Guzhuang Observation Station of the Nantong Central Station. A turning point in the daily average ground resistivity was identified, decreasing from February to April 2022 and slightly increasing from April 18, 2022, differing from the normal annual variation. The background information from the Nantong Central Station was examined in depth; the environment surrounding the geoelectric observation site were analyzed. The equipment status and stability of the observation site calibration were determined. The meteorological factors as well as typical monitoring data interferences and their causes were studied. The observed resistivity data from the geoelectric field were compared with those and from other stations in Jiangsu, and anomalies were analyzed to determine whether the differences between stations were caused by rainfall. This study provides a reference for future data analysis and determining seismic activity trends around ground resistivity stations.