Preliminary Report On The 8 August 2017 M-S 7.0 Jiuzhaigou, Sichuan, China, Earthquake

The 8 August 2017 M-s 7.0 Jiuzhaigou earthquake was the largest event in continental China in the recent 3 yrs. It occurred at the north boundary of the Bayan Har block. The mechanism of the mainshock exhibited strike-slip faulting. Relocation of the aftershock sequence revealed a south-southeast-striking near-vertical plane, which is consistent with the south-southeast nodal plane of the focal mechanism. The earthquake was considered to rupture a branch of the eastern Kunlun fault system. The earthquake sequence was characterized by a relatively lower aftershock productivity and normal decay rate. Static Coulomb stress calculation suggested that the Jiuzhaigou mainshock was encouraged by the 2008 M-s 8.0 Wenchuan earthquake and promoted several faults in this region, such as the middle and western segment of the Tazang fault, the Minjiang fault, and the Xueshanliangzi fault. The maximum intensity was IX on the Chinese intensity scale.