Changes in apparent resistivity and its possible mechanisms before the Luding Ms6. 8 earthquake on September 5, 2022, Sichuan province, China

There were five DC apparent resistivity stations in normal operation in Sichuan province before the Luding M(s)6. 8 earthquake occurred on September 5, 2022. Four stations, i. e., Hongge, Mianning, Jiangyou, and Garze, showed different types of medium-short term anomalies before the earthquake. The relationship between these anomalies of the four stations and the late seismogenic process is preliminarily analyzed in this paper, based on the results from rock physics experiments, the resistivity model, and the fault virtual dislocation model. The results show that the anomalies recorded by stations of Mianning, Jiangyou, and Garze are consistent with the relative deformation characteristics of the areas where the three stations are located. Apparent resistivity of Garze station showed decline changes and it was in an area of compression enhancement caused by the seimogenic process of this earthquake. Mianning and Jiangyou stations showed rise changes and they were in areas of relative extension. Hongge station showed decline changes, but it was in an area of relative extension. The anomalies recorded by Hongge station may not only be affected by the seimogenic process of the Luding n6. 8 earthquake.