Investigating the Slip Rate of the Main Frontal Thrust in the Eastern Himalaya, NE India

研究印度东北部喜马拉雅山东部主锋面推力的滑移率

• 批准号: 1145038
• 负责人: An Yin
• 金额: $ 24.88万
• 依托单位: University of California-Los Angeles
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-03-15 至 2015-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1145038&HistoricalAwards=false
• 关键词: Investigating; Slip; Rate; Main; Frontal

The 2500-kilometer-long Himalayan Main Frontal Thrust is the longest active thrust fault in the world. It links the oceanic subduction zones via active left-slip and right-slip transpressional systems on the east and west sides of the Indian subcontinent. Together, these active faults accommodate on-going northward indentation of the Indian plate into the Eurasian plate and this deformation contributes to the current growth of the Himalayan mountain belt. Although the Main Frontal Thrust may have absorbed more than 50% of the total current India-Asian convergence in the central Himalaya, how its slip rate varies along strike remains poorly known. For example, it is not clearly if the Main Frontal Thrust slip rate increases from west to east corresponding to the eastward increase in the rate of India-Asia convergence. Resolving this problem is a key to establishing the dynamic cause of the Himalayan formation. A major difficulty in determining the slip-rate distribution of the Main Frontal Thrust is the lack of geologic information on the Main Frontal Thrust in the eastern Himalaya. This NSF-funded project is addressing this issue by conducting detailed structural, morphologic, and geochronologic investigations. The final products of the project include (1) a robust estimate of the Quaternary slip rate on the Main Frontal Thrust in the eastern Himalaya, and (2) a first detailed active-fault map of the eastern Himalaya. This research project will benefit seismic-hazard evaluation of NE India that hosted the devastating 1897 M = 8.6 Assam earthquake along the northern edge of the Shillong Plateau and 1950 M = 8.5 Metog earthquake at the eastern end of the Himalaya. The final report of our findings on the distribution of active structures and the rates of active faults in the eastern Himalaya will be submitted to the local and central Indian governments. In addition to the scientific objectives of this study, the project is supporting the training and research efforts of a U.S. graduate student at UCLA, as well as collaboration with Indian researchers and graduate students. The project is supported by the EAR Tectonics Program and the OISE Global Venture Fund.

长达2500公里的喜马拉雅主额前推力是世界上最长的主动推力故障。它通过在印度次大陆的东部和西侧的主动左滑动和右滑动系统连接海洋俯冲带。这些主动断层共同将印度板块的北向北缩进到欧亚板块中，这种变形有助于喜马拉雅山带的当前生长。尽管主要的额叶推力可能吸收了喜马拉雅地区当前印度 - 亚洲融合的50％以上，但其滑动速度如何随罢工而变化。例如，从西部到东部的主要额叶推力速率与印度 - 亚洲 - 亚洲融合率的增长相对应，这并不清楚。解决这个问题是建立喜马拉雅阵型的动态原因的关键。确定主要额叶推力的滑动率分布的主要困难是缺乏关于喜马拉雅东部主要额叶推力的地质信息。这个由NSF资助的项目通过进行详细的结构，形态学和地质学研究来解决这个问题。该项目的最终产品包括（1）对喜马拉雅东部主要额推的第四纪滑移速率的强劲估计，以及（2）首次详细的喜马拉雅东部的详细主动型不良地图。该研究项目将使印度NE的地震危害评估受益于1897年毁灭性的1897 M = 8.6阿萨姆邦地震沿西隆高原北部边缘，在喜马拉雅山脉东端的1950 M = 8.5 Metog地震。我们关于主动结构分配和东部喜马拉雅东部积极故障率的发现的最终报告将提交给地方和中部印度政府。除了本研究的科学目标外，该项目还支持UCLA的美国研究生的培训和研究工作，以及与印度研究人员和研究生的合作。该项目得到了耳朵构造计划和OISE全球风险基金的支持。