Relocation and focal mechanism inversion for the Changning，Sichuan，earthquake on 7 June 2019

In this study, we apply the double-difference relocation technique and W-phase method to relocate the 2019 Changning, Sichuan, earthquake sequence, and to determine the focal mechanisms of the M＞4.5 aftershocks using the seismic data provided by the Earthquake Catalog System and China Earthquake Networks Center. The relocated epicentral locations of Changning earthquake sequence show a NW-striking dominant narrow belt in the predominant epicentral depth range of 5−10 km with a near vertical seismogenic fault plane. The focal parameters for the main shock of 17 June, 2019 Sichuan Changning earthquake are: strike 12°, dip 50°, strike 139° for the nodal plane Ⅰ , and strike 131°, dip 59°, strike 48° for the nodal plane Ⅱ , focal depth is 7.5 km and moment magnitude is M_W5.74. Moreover, the M＞4.5 aftershocks show a similar focal mechanism to the main shock. Combined analyses of the relocated epicentral location, focal mechanisms and tectonic settings suggest that the seismogenic fault of 17 June 2019 Changning main shock could be related to the thrust fault developed in north-eastern wing of NW-SE-striking Changning-Shuanhe anticline.