【摘要】 应用 P波初动符号资料 ,求解得到了岫岩 -海城 5.4级地震前、主、余震 2 0个 ML ≥ 4.0的震源机制解。分析表明 ,该地区的主压应力轴 (P)大多为 NEE- SWW向 ,主张应力轴 (T)大多为 NNW- SSE向 ,P、T轴仰角基本上小于 30°,表明力轴以水平者最多。N轴大多较陡。A、B节面的走向分别为 NWW向和 NNE向。岫岩 -海城地震主要为走滑断层类型。余震震源机制解绝大多数与主震相近 ,结果比较稳定 ,表明余震的应力场主要受主震震源应力场的控制更多还原

【Abstract】 In this paper, the focal mechanisms of 20 earthquakes with M L ≥4.0, including the foreshock, mainshock and aftershock of Xiuyan Haicheng M=5.4 earthquake are obtained by using the sign data of P wave first motion. The analysis shows that the principal compressional stress axes P are mostly in the northeast east direction and the extensional axes T in the north northwest direction, both P and T dip angles less than 30° are nearly horizontal. The null axes N are mostly rather steep. The strike of the two nodal planes is along the north northeast and northwest west directions respectively and most Xiuyan Haicheng earthquakes belong to the strike slip type. Focal mechanisms of aftershocks are mostly similar to that of the mainshock and result is relatively stable. Source stress field of the mainshock controls the stress field of aftershocks.更多还原