Abstract: The landsat images of color composit mosaic of 1:500000 are used to identify the fault activity in the Qiangtan and its neighboring areas of about 500000km². Based on the image characteristics of fault,the identified faults are grouped into three types which are active in Holocene,late Plastocene,and early middle Quaterary,respectively. Considering earthquakes of this region since 1900,the activity of major faults are analyzed. For example,the Margaichace Ruolacuo fault zone located north to the Qiangtang basin is evidently of left lateral strike slip in Holocence. The Mani M7.5 earthquake of November 8,1997 occurred just at this fault showing the recent activity of this fault.

Key words: Fault activity, Satellite photograph, Xizang

摘要： 利用1/50万彩色合成镶嵌的卫星图像,对羌塘块体及邻近大约50万km²地区的断裂活动性进行分析判读。根据断裂的影像特征,将所判读的断裂分成全新世活动、晚更新世活动和第四纪早、中期活动3类。结合本世纪以来的地震活动,分析了主要断裂的活动性。例如位于羌塘盆地以北,全新世明显左行走滑的玛尔盖茶卡-若拉错断裂带上,1997年11月8日发生了玛尼7.5级地震,是该断裂带现代活动的表现。

关键词: 断层活动性, 卫星图片, 西藏