摘要
1 98 8年 1 1月 6日在云南省澜沧县和耿马县境内先后发生了 7.6级和 7.2级强烈地震。其中 7.2级地震在震中区小黑江两岸灰岩裸露区出现了具有构造意义的地裂缝带。采用断层滑动矢量法反演出形成上述地裂缝带的应力张量为 :σ1走向 2 2 3°,倾角 2 8°;σ2 走向 42°,倾角6 2°;σ3 走向 1 3 3°,倾角 0°;应力比 R=0 .5 7,总体显示出走滑兼压性特征 ,基本代表了震源机制解所反映的震源应力场特征。
On Nov.6,1988,two strong earthquakes with M7.6,M7.2 occurred respectively in Lanchang and Gengma county,Yunnan Province.The tectonic rapture distributed in the limestone region along the two sides of Xiaohejiang River in the epicentral area. The stress tensors reversed from the rupture zone with fault slip vector method are:the azimuth of σ 1 is 223°,the dip angle is 28°;the azimuth of σ 2 is 42°,the dip angle is 62°;the azimuth of σ 3 is 132°,the dip angle is 0°;the ratio of stress R=0.57.As a whole,,it shows slip and compressive character,which is consistent with the stress field character indicated by the focal mechanism.The analysis to the fault slip vector can be as a method to determine whether a ground fissure is tectonic.
出处
《华北地震科学》
2001年第2期21-26,共6页
North China Earthquake Sciences
