Geoelectric anomalies before the two M6 earthquakes in northern Tianshan in 2016-2017

In the process of stress accumulation of underground medium, the fracture structure of rock mass will change, thus the dominant azimuth of geoelectric field ET will change. This paper collects the data of geoelectric minute values of Xinjiang from 2016 to 2017, and analyzes the geoelectric field anomalies utilizing the dominant azimuth method of geoelectric field before the Hutubi M6.2 earthquake on December 8, 2016 and the Jinghe M6.6 earthquake on August 9, 2017 in the northern Tianshan region. Significant geoelectric field anomalies, i.e., deflection of dominant orientation of cracks and large jump, are shown on Urumqi and Karamay stations around the epicenters before these two earthquakes. These phenomena also have features of time quasi-synchronization and site selectivity, showing short-term and imminent abnormal information. The results demonstrate that the geoelectric analysis method is effective in short-term earthquake prediction and accumulate experience and examples for earthquake prediction by geoelectric field method in the future.