雅鲁藏布大峡谷地区构造和地震活动特征  

Tectonic Characteristics and Seismic Activities of Yaluzangbu Grand Canyon,Tibet,China

作　　者：邵翠茹[1] 尤惠川[1] 曹忠权 王椿镛[1] 唐方头 张德成[4] 楼海[1] 胥广银[1] 常利军[1] 杨歧焱[5] 美朵 谢平 俞岗[6] 

机构地区：[1]中国地震局地球物理研究所,北京100081 [2]西藏自治区地震局,拉萨850000 [3]地壳运动监测工程研究中心,北京100036 [4]中国地震局地震预测研究所,北京100036 [5]中国地震局地壳应力研究所,北京100085 [6]中国地震局地质研究所,北京100029

出　　处：《震灾防御技术》2008年第4期398-412,共15页Technology for Earthquake Disaster Prevention

基　　金：中国水电工程顾问集团公司科技项目(CHC-KJ-2007-12-01)资助

摘　　要：雅鲁藏布大峡谷地区位于喜马拉雅东构造结前锋地带,新构造运动和地震活动都十分强烈,两者关系密切。区内发育有北北东-北东向和北西西-北西向两组断裂构造,调查研究表明,它们的规模、性质、活动时代、活动强度等特征具有明显的差异:北西西-北西向断裂规模较大,多为逆冲、逆走滑断层,形成较早;北北东-北东向断裂单条规模相对不大,常集中分布,构成北北东向的剪切拉张断裂构造带,形成较晚,第四纪晚期活动明显。强震主要发生在喜马拉雅山差异运动强烈地带或地段,如块体周边的深大断裂带及其附近。7级以上地震主要与断裂构造带中规模较大、全新世强烈活动段、断裂几何构造复杂部位或多组方向断裂交汇密切相关。其中,7.5级以上地震发生在断裂构造带中走滑分量较大的北西向和北东向断裂带上。Yaluzangbu grand canyon is located in the front belt of Himalaya tectonic joint, where the intensity of both notectonics and seismic activities are very strong. There are two predominant groups of faults in the area in NNE-NE strike and NWW-NW strike respectively. Investigation shows that there exist distinctive differences in scale, mode, active time and active intensity between these two groups of faults. NWW-NW strike fault is relatively in large acale with trust to striking slip mode and ole forming age. Whereas, NNE-NE strike fault is in relatively small scale, with extensional characters and relatively new forming age. Strong earthquakes occurred mainly along the deep and large fault and its adjacent area where the differential movement is strong. The occurrence of earthquakes with magnitude of 7 are related with geometrically complicated positions or the joint of several faults with modium scale. Generally, the earthquake with magnitude over 7.5 mainly occurred along NW and NE strike faults with large proportion of strike-slip movement.

关 键 词：雅鲁藏布大峡谷 构造 地震 

分 类 号：P548[天文地球—构造地质学] P315[天文地球—地质学]