摘要
本文从活动断裂、水系分布方向、地震震源机制解三个方面,对上海及邻区新构造应力场进行了探讨。从新构造期活动断裂的力学性质分析,本区主压应力场方向为北东东至近东西;从水系河谷分布的优势方向推论出的主压应力场方向为96°左右;用本区56个地震震源机制解的 P轴赤平极射投影的极点统计分析法,确定主压应力方向约为80°;三者大体一致,说明它们是同一构造应力场的产物,其主压应力场方向为近东—西向。
The active faults,valley trends and fault plane solutions of earthquake data are used todetermine the Neotectonic stress directions in Shanghai and its vicinity.In accordance with the mech-anical properties of active faults,the principal compressive stress tends to NEE and approximatelyE-W directions.The valley trends show that the direction of the principal compressive stress is about96 degree.Based on the point contour diagram of fifty-six p-axes of fault plane solutions,themaxmum compressive stress is about 80 degree.These three methods show that the principalNeotectonic compressive stress in this region is approximately in the E-W direction.Theyare produced by the same tectonic stress field.
关键词
活动断型
地震
震源
构造应力场
active faults
valley trends
fault plane solution of earthquakes
principal compressive stress
