利用西藏地震台网记录的波形数据，采用CAP方法，反演2017年11月18日西藏米林M 6.9地震震源机制解，并绘制余震空间分布。反演得到，节面Ⅰ：走向285°，倾角47°，滑动角70°；节面Ⅱ：走向133°，倾角46.6°，滑动角110.1°，矩心深度约19.0 km。结果显示，此次地震是逆冲为主兼少量走滑型地震，节面Ⅰ走向与NW向嘉黎—察隅断裂走向一致，余震空间展布也与断裂走向一致。
In the article, we have used CAP method and local broadband waveform data to determine the focal mechanism of Milin M 6.9 earthquake in Tibet on Nov.18, 2017. The result shows that the best double couple solution of the M 6.9 event is 285°, 47°, 70°for strike, dip and rake angles respectively. The other nodal plane is 133°, 46.6°, 110.1°; The estimated focal depth is about 19.0 km. The result shows that the event is thrusting and minor strike slip earthquakes, one strikes of the two nodal plane are same to strike of Jiali-Chayu fracture. At the same time, the spatial distribution of aftershocks is consistent with fault strike.
2017,38(6): 26-29 收稿日期：2017-11-23
DOI：10.3969/j.issn.1003-3246.2017.06.005
作者简介：吴宝峰(1979—),男,黑龙江绥化人,硕士,工程师,主要从事地震监测预报工作
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