Fault parameters and rupture process of the Jinghe M_S6.6 earthquake in 2017

We estimated the fault geometrical parameters and source rupture details of the Jinghe M_S6.6 earthquake on August 9, 2017 by inverting teleseismic, near-field strong-motion and InSAR data. In order to determine the fault geometrical parameters, we conducted a 3-D grid search process by performing geodetic slip inversions with InSAR data, and found theoptimal values of fault strike, dip and hypocentral depth to be 95°, 47° and 14 km, respectively. Joint inversion of rupture process based on the searched fault model shows a unilateral rupture model with a maximum slip of 0.8 m. Slips mainly concentrate between 5−15 km to the west of the hypocenter, and 15−25 km along down-dip direction. Most ruptures occurred beneath 10 km depth. The average rake angle is about 106°, suggesting a purely thrust event of the earthquake. The obtained seismic scalar moment is 3.6×10¹⁸ N·m, equivalent to a magnitude of M_W6.3. The rupture duration is about 9 s, in which the rupture propagated with the velocity of 2.1−2.6 km/s. Attention to occurrence of earthquakes above 10 km depth in this area may be required, as most ruptures of this earthquake occurred beneath 10 km depth.