Features of seismicity in Xinjiang and its possible reason after the Yutian M_S7.4 earthquake, 2008

The paper discusses quantitatively the influence of the Yutian M_S7.4 earthquake of March 21, 2008 and Wuqia M_S6.9 earthquake of October 5, 2008 on regional seismicity in Xinjiang, and explains primarily the possible reason of earthquake activity feature in Xinjiang after the Yutian M_S7.4 earthquake by analyzing the static Coulomb failure stress change produced by the Yutian M_S7.4 earthquake and Wuqia M_S6.9 earthquake, and the seismicity feature of M_S≥3 earthquakes in the positive Coulomb stress change region of Kashi-Wuqia joint region, the central segment of Tianshan Mountain and Kalpin block. The result shows that the Yutian M_S7.4 earthquake of March 21, 2008, may encourage the Wuqia M_S6.9 earthquake of October 5, 2008, and the Yutian M_S7.4 earthquake and Wuqia M_S6.9 earthquake may change the seismicity state in the central segment of Tianshan Mountain, Kalpin block and Kashi-Wuqia joint region, and encourage the subsequent M_S≥3 earthquakes.