High Resolution Upper Mantle Structure beneath the Tibetan Plateau and Its Surroundings from Studies of Seismic Waveforms

青藏高原及其周围地区高分辨率上地幔结构的地震波形研究

• 批准号: 0439992
• 负责人: Lupei Zhu
• 金额: $ 11.35万
• 依托单位: Saint Louis University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-05-01 至 2008-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0439992&HistoricalAwards=false
• 关键词: Resolution; Upper; Mantle; Structure; beneath

Mountain building by continent-continent collision is the mostimportant orogenic process on Earth whose mechanism is notwell understood. The collision between India and Asia is thelargest region of such collision and has produced the world's mostspectacular topography. Within this region, the Tibetan Plateaustands out as a natural laboratory in which we can test hypothesesregarding a fundamental process that has impacted continentaldynamics. Collision models, obtained in various studies, predictsignificantly different upper-mantle structure beneath the plateau.The upper mantle, therefore, holds a key to differentiating betweenpossible collisional models and to unraveling how this archetypeof plateaus came into being. The objective of this research isto determine high resolution 3-D upper-mantle P and S velocitystructure beneath the Tibetan Plateau and neighboring regions.The PIs will collect and process available seismic waveformdata of more than 300 broadband stations in the study area fromearthquakes in the upper-mantle distance range. These studiesshould provide much improved lateral and depth resolution in theupper mantle than it has been possible in all previous studies.The results of the proposed study can be used to verify or dismissexisting collision models and to develop new ones. The researchtopic is also closely related to several undergraduate and graduatecourses (plate tectonics and geodynamics) that the PI is currentlydeveloping and teaching at SLU. The proposed research involvescollaboration between Saint Louis University and the Institute ofGeophysics, Chinese Earthquake Administration. It will use seismicdata collected by several multi-national (China, France, Germany,USA, etc) projects in Tibet.

陆-陆碰撞造山作用是地球上最重要的造山过程，但其机制尚不清楚。 印度与亚洲的碰撞是此类碰撞中最大的区域，并产生了世界上最壮观的地形。在这一地区，青藏高原作为一个天然实验室脱颖而出，我们可以在其中测试关于影响大陆动力学的基本过程的假设。 各种研究中获得的碰撞模型预测了高原下明显不同的上地幔结构。因此，上地幔是区分可能的碰撞模型和揭示这种高原原型如何形成的关键。 本研究的目的是确定青藏高原及邻区上地幔高分辨率三维P、S速度结构，PI将收集和处理研究区300多个宽频带台站上地幔距离范围内地震的有效地震波形资料。 这些研究将提供比以往所有研究更高的上地幔横向和深度分辨率，其结果可用于验证或否定现有的碰撞模型，并开发新的碰撞模型。 该研究课题也密切相关的几个本科生和研究生课程（板块构造和地球动力学），PI目前正在开发和SLU教学。 该研究计划由圣刘易斯大学和中国地震局地球物理研究所合作完成。 它将使用在西藏的几个多国（中国、法国、德国、美国等）项目收集的地震数据。