CURRENT CRUSTAL MOTIONS IN NEPAL AND SOUTHERN TIBET

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• 出版年：2002
• 作者：YANG Zhigiang；JEFFERY T.Freymuller；WANG Wenying
• 单位1：Shool of Geological Engineering and surveying Engineering, Chang an University
• 单位2：The National Centre for Time Service of Chinese Academy of Sciences
• 出生年：1961
• 职称：教授
• 语种：英文
• 作者关键词：GPS；Crustal motions；Tibet
• 起始页：30
• 总页数：7
• 经费资助：中美国际合作项目。
• 刊名：工程地质学报
• 是否内版：是
• 刊频：季刊
• 创刊时间：1993
• 主办单位：中国科学院地质与地球物理研究所
• 主编：王思敬
• 地址：北京市9825信箱
• 邮编：100029
• 电子信箱：gcdz@mail.igcas.ac.cn
• 网址：http://www.chinainfo.gov.cn/periodical/
• 卷：10
• 期：05
• 期刊索取号：P470.66107

摘要

Repeated GPS surveys in Nepal and southern Tibet provide a direct measurement of current crustalmotions。GPS surveys have been carried out in the region by U. S. ，Nepalese and Chinese scientists since 1991.We have measured （17±3）mm/year of contraction between sites in southern Tibet and stable peninsular India，concentrated in a north-south zone 120 km wide at the surface. GPS and leveling observations are consistentwith an abrupt transition from a slipping to locked interface at a depth of about 20 kin。We infer India to be un-derthrusting Tibet at a rate of （20±3）mm/a，and predict additional elastic deformation north of our network。East-west extension of southern Tibet is observed at a rate of （6±3） mm/year between Lhasa and the Mt。Everest region，and （12±3）m/a relative to western Nepal。This rate is consistent with a simple model in whichthe Tibetan overthrust wedge extends to maintain arc-normal slip vectors all along the Himalayan are。Addi-tional measurements to be carried out over the next three years will refine these models and extend the spatial ex-tent of our measurements to include more of the Tibetan plateau.