Collaborative Research: A Paleoseismic Record of Repeated Great Earthquakes on the Sunda Subduction Megathrust, Northern Sumatra

合作研究：苏门答腊北部巽他俯冲断层反复发生大地震的古地震记录

• 批准号: 0635424
• 负责人: Harvey Kelsey
• 金额: $ 4.45万
• 依托单位: Humboldt State University Foundation
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-03-01 至 2008-02-29
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0635424&HistoricalAwards=false
• 关键词: Collaborative; Research; Paleoseismic; Record; Repeated

The 2004 Andaman-Aceh earthquake and tsunami focused global attention on the northernmost part of the Sumatran subduction zone and raised questions about the past geologic history of the Sunda megasthrust offshore of northernmost Sumatra. The objective of this research project is to understand the long-term seismic behavior of the Sunda megathrust of northernmost Sumatra through a study that integrates forefront techniques of paleoseismology, geodesy, geochronology and paleo-environmental reconstruction using microfossils. The study will establish a subduction zone chronology for the northernmost past of the Sumatran subduction zone offshore of northern Sumatra going back approximately five thousand years. The reconstructed subduction zone history will include investigation of several critical components that help define the nature of subduction zone tectonics at convergent margins. These components include recurrence interval between subduction zone earthquakes, amounts of coseismic and interseismic vertical land level changes, documentation of subsidence precursory to the main coseismic subsidence event, documentation of uplift after the main coseismic subsidence event caused by slow, down dip afterslip on the megathrust and finally, development of a chronology of tsunami that invades the Sumatran coast.Results of this research will help define the history of subduction zone earthquakes and tsunami along the west coast of northern Sumatra going back several thousand years. A long-term record of subduction zone earthquakes that spans at least three or four earthquake cycles will provide realistic estimates of the average time between earthquakes and tsunamis similar to the earthquake and ensuing tsunami that struck the west coast of northern Sumatra in December 2004. Results from this project will be disseminated among the inhabitants of the region and with Sumatran governmental agencies. These results will establish that earthquake and tsunami are recurrent events that should be anticipated and that require disaster planning.

2004年的安达曼-亚齐地震和海啸使全世界的注意力集中在苏门答腊岛俯冲带的最北端，并提出了关于苏门答腊岛最北端近海的舜达巨型逆冲带过去的地质历史的问题。这一研究项目的目的是通过一项综合了古地震学、大地测量学、年代学和利用微化石重建古环境的前沿技术的研究，了解苏门答腊岛最北端的舜他巨型逆冲带的长期地震行为。这项研究将建立大约5000年前苏门答腊岛北部近海苏门答腊岛俯冲带最北端的俯冲带年代学。重建的俯冲带历史将包括对几个关键成分的调查，这些成分有助于确定汇聚边缘的俯冲带构造的性质。这些组成部分包括俯冲带地震之间的重复间隔、同震和地震间垂直地面水平的变化量、主要同震沉降事件的前兆记录、由巨型逆冲上缓慢的向下倾斜的后滑引起的主要同震沉降事件后的抬升记录，以及入侵苏门答腊岛海岸的海啸年表的发展。这项研究的结果将有助于确定几千年前苏门答腊岛北部西海岸俯冲带地震和海啸的历史。至少跨越三到四个地震周期的俯冲带地震的长期记录将对地震和海啸之间的平均时间提供现实的估计，类似于2004年12月袭击苏门答腊岛北部西海岸的地震和随后发生的海啸。该项目的成果将在该地区居民和苏门答腊岛政府机构中传播。这些结果将证明，地震和海啸是应该预料到的反复发生的事件，需要进行灾害规划。