2016年新疆呼图壁6.2级地震发震构造

THE PRELIMINARY STUDY ON THE SEISMOGENIC STRUCTURE OF THE HUTUBI M_S6.2 EARTHQUAKE

文中利用新疆地震台网的震相报告,采用双差定位方法重新定位2016年12月8日新疆呼图壁M_S6.2地震及M_L1.0以上地震的震源位置,结果显示,余震沿NE和NW 2个方向展布,深度主要分布在5~15km范围内。同时利用新疆区域数字地震台网波形记录,采用CAP方法反演了呼图壁M_S6.2主震和部分余震的震源机制和震源深度。基于上述研究,综合分析了呼图壁6.2级地震的震源深度、震源机制和余震分布特征,探讨其发震构造。结果显示,呼图壁6.2级地震的最佳双力偶机制解节面Ⅰ走向144°、倾角26°、滑动角118°,节面Ⅱ走向293°、倾角67°、滑动角77°,矩震级M_W=5.9,矩心深度为15.2km,表明本次地震为1次逆冲型的地震事件。余震震源机制解大部分显示为逆冲型,与主震相似。推测本次地震的可能发震断裂为霍尔果斯-玛纳斯-吐谷鲁断裂。

Based on the phase report of Xinjiang Seismic Network,the Hutubi M S6.2 earthquake sequence M L≥1.0 was relocated by the HypoDD method.The results show that the aftershocks were distributed along NE and NW direction.The aftershocks were in the depths of 5~15km.In addition,by using the digital waveforms of Xinjiang Seismic Network,the best double-couple focal mechanism of the main shock and some aftershocks of M S≥3.8 were determined by the CAP method.Based on the above studies,the source depth,focal mechanism and aftershock distribution of the Hutubi M S6.2 earthquake were analyzed and the seismogenic structure was discussed.The nodal plane parameters of the best double-couple focal mechanism are strike 144°,dip 26°,rake 118°,and strike 293°,dip 67°,rake 77°,respectively.The moment magnitude M W is about 5.9,with centroid depth of 15.2km.These show that the main shock was a thrust type.Most focal mechanism solutions of the aftershocks were shown as a thrust type,which are similar to the main shock.It is speculated that the possible seismogenic fault of this earthquake is the Huorgosi-Manas-Tugulu Fault.