2014年新疆于田M_S7.3地震矩心矩张量快速测定

Rapid determination of the centroid moment tensor to the 2014 Yutian M_S7. 3 earthquake,Xinjiang

基于中国大陆中强震自动矩张量测定系统,采用虚拟中国地震台网记录的近震波形(震中距4°~12°),反演了新疆于田MS7.3地震的矩心矩张量。结果显示,地震发震断层面参数分别为走向243°/倾角70°/滑动角-18°,表现为1次左旋走滑为主兼有少量正倾滑分量的事件。矩心在水平方向上位于震中(36.123°N,82.499°E)以东约13 km,矩心深度约10 km。总标量地震矩M0为3.05×1019N·m,换算成矩震级MW6.92,推断震源破裂时大部分能量释放的持续时间约14s。同时探讨了自动矩张量测定系统在未来地震灾情预判中的重要作用。

The authors successfully employ an automatic centroid moment tensor inversion system to infer the centoid moment tensors of the Yutian MS7.3 earthquakes,Xinjiang using regional seismic waveforms （4° ＜Δ ＜ 12°） observed by the virtual China Seismic Networks,which has been recently set up.The results indicate that this event occurred on a rupture plane （strike 243°,dip 70°,and rake-18°）,showing a le^lateral strike-slip mechanism with minor normalfaulting component.The centroid in the horizontal direction is located at nearly 13km east of the epicenter （36.123°N,82.499°E）,and the best-fitting centroid depth is round 10km.The total scalar moment,M0,is retrieved with an average value of 3.05 × 1019N·m （or moment magnitude MW6.92）.Most of the energy is released within about 14s.Moreover,we discuss about the future application of the automatic centroid moment tensor inversion system in earthquake disaster decision.