2016年青海门源MS6.4地震重定位

利用中国地震科学台阵探测项目中部分台站和青海、甘肃地震台网的观测资料，选取最佳速度模型，利用逆时成像技术对2016年1月21日青海门源M_S6.4地震的起始破裂点和震源中心进行成像分析.结果表明:门源地震的发震时刻为北京时间2016年1月21日1时13分11 s，起始破裂点位于 (37.67°N，101.61°E)，震源深度为9.41 km；震源中心的位置变迁可以分为1—6 s和7—10 s两个阶段，且均基本位于倾角约75°、倾向NE的斜面附近.根据震源中心的迁移特征，推测走向为335°，倾角为56°，滑动角为97°的节面为门源地震的破裂面.结合该地震滑动角较大及高倾角逆冲构造的活动特征，认为门源M_S6.4地震应为冷龙岭北侧高倾角次级逆断层活动的结果. 

Relocation of the 2016 MS6.4 Menyuan,Qinghai earthquake

The rupture initiation point and hypocentoid of Menyuan M_S6.4 earthquake, which occurred on January 21, 2016, were imaged out by means of time-reversal imaging technique (TRIT) using velocity models and waveforms from regional seismic network and China Seismic Array. The results show that, origin time of Menyuan M_S6.4 earthquake was 01:13:11 on January 21, 2016 and rupture initiation point was at (37.67°N, 101.61°E), and the focal depth was 9.41 km. The migration of hypocentroid can be divided into two stages of 1--6 s and 7--10 s, which basically located at an inclined plane dipping to NE with an inclination about 75°. According to the characteristic of hypocentroid migration, we speculate that the nodal plane with strike of 335°, dip of 56° and rake of 97° is the rupture plane of Menyuan earthquake. Considering large rake angle, Menyuan earthquake shows characteristic of thrust tectonic activities with high dip angle, so we are likely to convince that Menyuan earthquake resulted from new activity of north Lenglongling secondary thrust fault with high dip angle.