河北南部及邻近地区中小地震震源机制特征分析

Analysis of focal mechanism characteristics of small and medium earthquakes in southern Hebei and its adjacent areas

利用P波初动和振幅相结合的广义极性振幅技术法(GPAT),反演2007-2016年河北南部及邻近地区发生的368个ML≥2.0中小地震震源机制解,利用统计方法和系统聚类方法,分析震源机制解参数特征。结果表明,河北南部及邻区中小地震以走滑地震为主;正断层和逆断层相对较少,断层面以倾斜或直立为主,断层运动表现为左旋走滑和右旋走滑,应力作用以水平和近水平推扭方式为主。

In this paper, the generalized polar amplitude technique(GPAT) combined with P-wave initial motion and amplitude is used to invert the focal mechanism solutions of 368 ML≥ 2.0 small and medium-sized earthquakes occurred in southern Henan and its adjacent areas from 2007 to 2016. The parameters of the focal mechanism solution parameters are analyzed by statistical methods and system clustering methods. The results show that the focal mechanism solutions of the small and medium-sized earthquakes in the southern part of Hebei Province and its adjacent areas are characterized by left-lateral strike-slip and right-lateral strike-slip. The high dip angle of the fault plane is mainly inclined or upright;the normal fault and the reverse fault are relatively less, the strike-slip earthquake is the main means that the stress mode is a horizontal and near-level push.