Collaborative Research: Earthquake Geology of the Pakistani Himalaya: Characterizing Slip Rates and Recurrence of Potentially Devastating Earthquake Sources

合作研究：巴基斯坦喜马拉雅山的地震地质：表征滑移率和潜在破坏性地震源的复发

• 批准号: 0635987
• 负责人: Andrew Meigs
• 金额: --
• 依托单位: Oregon State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-02-01 至 2011-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0635987&HistoricalAwards=false
• 关键词: Collaborative; Research; Earthquake; Geology; Pakistani

The magnitude 7.6 Kashmir earthquake of October 8, 2005 caused the deaths of more than 73,000 people, the greatest loss of life of any earthquake in the Indian subcontinent. It also was Pakistan's worst natural disaster of any kind, a source of alarm to the governments of Pakistan and India because both countries share the seismically-active and increasingly urban-populated Himalaya. Large, devastating earthquakes in the Himalaya are thought to be associated with the Himalayan basal decollement, the India-Asia plate boundary. Historic earthquakes in the past two centuries have ruptured this fault but have not reached the surface at the Himalayan thrust front. In contrast, surface rupture at the thrust front did occur in Nepal and northwest India approximately 900 and 600 years ago, respectively. In the northwestern Himalaya of Pakistan, it is unknown whether ruptures occur at the thrust front during plate-boundary earthquakes. The 2005 Kashmir earthquake occurred on a fault within the orogenic belt and not at the thrust front, which indicates that some of the India-Asia convergence in Pakistan is absorbed by internal faults. A second major unknown is how strain and convergence are partitioned between the internal faults and the frontal thrust fault systems. The Oregon State University and California State University, Northridge, research team are conducting a three-year research project with the goal of constraining the India-Asia plate boundary earthquake cycle in Pakistan in order to provide the first constraints on the earthquake recurrence and slip rate of active structures. These data represent a much-needed first step in seismic hazard characterization of faults threatening major population centers (Islamabad, Rawalpindi, and Peshawar have a combined population of approximately 6,000,000).Plate boundary earthquakes in the Himalaya threaten an ever-increasing population across a region in harm's way that is likely to be widely affected by the next great Himalayan earthquake. Over forty million people live in the Ganges plain south of the Himalaya, and the Himalayan foothills are dotted by numerous cities ranging in size from about 500,000 to more than 2 million people. The nearly 80,000 deaths in Pakistan during the 2005 Kashmir earthquake emphasize the magnitude of the hazard associated with Himalayan earthquakes. Although Pakistan has had historic devastating earthquakes (1935 Quetta, 35,000 killed), the country as a whole is largely unprepared for future events and does not have a cadre of scientists trained in earthquake geology. In this project, the scientific team will determine the earthquake history of key active faults in Pakistan and simultaneously train Pakistani scientists in the techniques used widely around the world to constrain earthquake hazard in the field. The scientific contribution of this project will be a new understanding of how the India-Asia collision is manifested by earthquakes in the northwest Himalaya. The societal legacy of this project will be new information on probabilistic forecasting of large earthquakes threatening some of the major population centers, leading to improved building codes and disaster prevention, and a new generation of scientists trained in the modern techniques of earthquake science. These Pakistani earth scientists will be equipped to carry forward into the future a systematic characterization of seismic hazards and earthquake history of active faults in Pakistan.This award was co-funded by NSF's Office of International Science and Engineering.

2005年10月8日，克什米尔发生7.6级地震，造成73，000多人死亡，是印度次大陆地震中死亡人数最多的一次。这也是巴基斯坦最严重的自然灾害，对巴基斯坦和印度政府来说是一个警报来源，因为这两个国家共享地震活跃和城市人口日益增加的喜马拉雅山。在喜马拉雅山发生的破坏性大地震被认为与喜马拉雅山基底滑脱（印度-亚洲板块边界）有关。过去两个世纪的历史性地震已经破坏了这个断层，但还没有到达喜马拉雅冲断层前缘的表面。与此相反，尼泊尔和印度西北部的逆冲断层前缘分别在大约900年和600年前发生了地表破裂。在巴基斯坦的喜马拉雅山西北部，板块边界地震期间，断层前缘是否发生破裂尚不清楚。2005年克什米尔地震发生在造山带内的一个断层上，而不是在逆冲前缘，这表明巴基斯坦的一些印度-亚洲会聚被内部断层吸收。第二个主要的未知数是内部断层和前缘逆冲断层系统之间的应变和会聚是如何分配的。俄勒冈州州立大学和加州州立大学北岭分校的研究小组正在进行一项为期三年的研究项目，目标是限制巴基斯坦的印度-亚洲板块边界地震周期，以便对地震复发和活动结构的滑动率提供第一个限制。这些数据代表了对威胁主要人口中心（伊斯兰堡、拉瓦尔平迪和白沙瓦的总人口约为6，000，000）的断层进行地震危险性表征的迫切需要的第一步。喜马拉雅的板块边界地震威胁着整个地区不断增加的人口，其危害方式可能会受到下一次喜马拉雅大地震的广泛影响。超过4000万人生活在喜马拉雅山脉以南的恒河平原，喜马拉雅山麓遍布着众多城市，规模从50万到200多万人不等。2005年巴基斯坦克什米尔地震造成近80 000人死亡，突出表明了喜马拉雅地震的危害程度。虽然巴基斯坦历史上曾发生过毁灭性地震（1935年奎达，35，000人死亡），但整个国家对未来的事件基本上没有准备，也没有受过地震地质学训练的科学家骨干。在该项目中，科学小组将确定巴基斯坦主要活动断层的地震历史，同时培训巴基斯坦科学家掌握世界各地广泛使用的技术，以限制实地地震灾害。该项目的科学贡献将是对印度-亚洲碰撞如何通过喜马拉雅山西北部的地震表现出来的新认识。该项目的社会遗产将是关于威胁一些主要人口中心的大地震概率预测的新信息，从而改进建筑规范和防灾，以及新一代接受地震科学现代技术培训的科学家。这些巴基斯坦地球科学家将有能力在未来对巴基斯坦活动断层的地震危险和地震历史进行系统的描述。该奖项由美国国家科学基金会国际科学和工程办公室共同资助。