Influence of a geomagnetic storm on geo-resistivity observation and analysis of its physical mechanism

Based on observation data from five survey points within the Jilin regional geo-resistivity observation network, this study systematically analyzes the influence of a geomagnetic storm event with K_p index of 9 that occurred in May 2024 on ground resistivity observation and its physical mechanism. Results show that a geomagnetic storm will have a significant impact on the observation of geo-resistivity, which is mainly manifested as an obvious abnormal jump and even distortion of the observation data. By comparing and analyzing the observation data from different measuring points during the geomagnetic storm and during the quiet period, the specific manifestations and duration of the geomagnetic storm are revealed. The analysis of the physical mechanism shows that when the geomagnetically induced current generated during the geomagnetic storm flows in the crust, a strong electric field is induced on the surface, forming an additional “induced electric field”, which leads to a sudden change in the earth resistivity data. This study not only enriches the theoretical understanding of interference factors in earth resistivity observation but also provides an important reference for data tracking analysis and anomaly discrimination in practical observation work.