ANALYSIS ON APPARENT RESISTIVITY VARIATIONS OF KEPING STATION BEFORE 2020 JIASHI MS6.4 EARTHQUAKE
On January 19,2020,the Jiashi MS 6.4 earthquake occurred near the Keping nappe in the west of the southern Tianshan Mountains in Xinjiang.The analysis of the Keping ground resistivi-ty observation data at 169 km from the epicenter shows that since October 2017,the two-component ground resistivity observation values of the Keping station have shown obvious abnormal rate chan-ges.The NS-direction abnormal change range is-2.33％,and the EW-direction is-0.72％.At the same time,the two components showed anisotropic changes,and the anisotropy S decreased rap-idly.In order to explore whether there is a mechanical mechanism between the Keping ground resis-tivity anomaly and the Jiashi MS 6.4 earthquake,this paper calculates the distribution of stress and strain in the observation point area before the earthquake by the fault virtual dislocation model,and combines the P-axis direction calculated by the focal mechanism solution.It is found that the ab-normal change of Keping ground resistivity before the earthquake is related to the earthquake.
Jiashi MS6.4 earthquakeKeping station apparent resistivityAnomaly variationFault virtual dislocation model
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