Collaborative Research: Kinematics and Strain Localization in the Himalaya and Tibet

这个项目旨在了解两个大陆板块——印度和亚洲之间碰撞的细节。GPS（全球定位系统）大地测量学将用于测量分布在印度北部平原和西藏北部塔里木盆地之间部分碰撞区的大约100个点的运动。特别是，P.I.s对发生在西藏南部和大喜马拉雅地区的独特过程很感兴趣，因为这些地区似乎靠近大地震的成核带，这些大地震的未来再次发生将对印度北部和尼泊尔的人口造成灾难性的影响。这项研究基于他们1997年的发现，即喜马拉雅山脉正以每年21+-3毫米的速度向南收缩，但这种收缩主要集中在不到100公里宽的区域。西藏似乎也在以每年5-10毫米的速度收缩。观测表明，喜马拉雅的收缩很可能主要是弹性的（应变能为未来的大地震发展），而西藏的深度收缩主要是塑性的（驱动高原东西扩张和地表地震活动）。P.I.s提出的测量方法旨在提供这些过程背后的物理约束，以及它们之间过渡区域的细节。＊＊＊

9725563 Freymueller This project is aimed at understanding the details of the collision between two continental plates - India and Asia. GPS (Global Positioning System) geodesy will be used to measure the motion of some 100 points distributed throughout parts of the collision zone, between the northern plains of India, and the Tarim basin north of Tibet. In particular, the P.I.s are interested in the unique processes that occur beneath southern Tibet and the Greater Himalaya because these appear to be close to the nucleation zone of great earthquakes whose future recurrence will be disastrous to the populations of northern India and Nepal. The study builds on their 1997 finding that the Himalaya are contracting north-south at a rate of 21+-3 mm/year, but that this contraction is largely concentrated in a zone less than 100 km wide. It appears that Tibet may also be contracting at 5-10 mm/year. Observations indicate it is probable that Himalayan contraction is largely elastic (strain energy developing for future great earthquakes), and that Tibetan contraction at depth is largely plastic (driving east-west expansion of the plateau and surface seismicity). The measurements the P.I.s propose are designed to provide constraints on the physics underlying these processes, and details of the transition zone between them. ***