摘要
在文献［３］提出的用计算机确定震源断层面解的基础上，进一步给出了解的置信度。置信度由两个因子组成（Ｃ_１，Ｃ_２）。其中Ｃ_１为初动符号的符合比，Ｃ_２为解的不可变动空间与全部空间的比。使用长江三峡及邻区（北纬２８°－３４°，东经１０８°－１１４°）１９７４年以来的初动观测资料，确定了Ｍｓ≥２．１的４０次地震的断层面解、该区的区域应力场和分区应力场及平均错动性质。此外还给出了黄陵背斜地区的应力场特征。结果表明，黄陵背斜的地震构造活动具有整体性，构造过程发生在１５～２０ｋｍ的深度，张应力轴的方向分布显示以背斜为中心的幅射状态。
Based on the method of determining fault plan solution by computer in the reference[3] ,the confidence of the solution which consists of two factors(C1,C2) is difined.Where C1 is the coincidence ratio between the symbols in first motions and C2 is the ratio between the unchangeable space and the all space in fault plan solution. With the data of first motion observation in the Yangtze Gorges and its vicinity (N 28°～34°,E 108°～114°) from 1974 the fault plan solutions of 40 earthquakes (Ms≥2.1)and the local and sublocal stress fields as well as the mean faultting characteristices are determined.In addtion,the characteristics of stress field in the Huangling anticline area are given. It is concluded that the seismic-tectonic activity of the Huangling anticline area behave as whole and the tectonic process is under way in the depth of 15￣20 km as well as direction distribution of tensile stress axes appears radioactive from the centre of the anticline.
出处
《地壳形变与地震》
CSCD
1994年第2期1-12,共12页
Crustal Deformation and Earthquake
基金
国家科学技术委员会"七.五"攻关课题
关键词
构造应力场
地震
震源
错动类型
focal mechanism, fault plan solution , faulting types ,Yangtze Gorges
