Experimental investigations on the deformation behavior of sediment in the shallow region of the Nankai, North Sumatra, and Aleutian subduction zones

南海、北苏门答腊和阿留申俯冲带浅部沉积物变形行为的实验研究

• 批准号: 1654586
• 负责人: Hiroko Kitajima
• 金额: $ 23.45万
• 依托单位: Texas A&M University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-06-01 至 2020-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1654586&HistoricalAwards=false
• 关键词: Experimental; investigations; deformation; behavior; sediment

The main objective of the work is to characterize the physical properties of sediments at subduction zones. Experiments on sediments from the Nankai Trough and the Sumatra and Aleutians Trench will be conducted at the rock mechanics laboratory at Texas A&M University. The experiments will be run at high pressure and temperature conditions to simulate the conditions that the sediments encounter as they are carried deep into the earth as one tectonic plate plunges beneath another. The project results will aid in understanding slip on faults and the potential for tsunami generation at subduction zones worldwide. This project will support an early-career female researcher as a GeoPRISMS post-doctoral fellow.This research aims to understand deformation behavior in the shallow portion of subduction zones where greater displacement and ground deformation can occur in response to megathrust earthquake ruptures. This project will address key fundamental questions about whether the shallow near-trench portion of a subduction zone is locked and accumulating strain or fully creeping. Consolidation and creep experiments will be conducted at elevated pressures and temperatures and at a range of strain rates on sediment samples from three different subduction systems - Nankai Trough, Sumatra, and Aleutian subduction zones. The research goals of the project are to 1) characterize the elastic, plastic, and viscous deformation behaviors as a function of pressure, temperature, strain rate, and sediment lithology and 2) assess the potential for strain accumulation and co-seismic slip rupture propagation in the shallow near-trench regions of subduction zones. The project will advance knowledge of strain accumulation, fault coupling, and slip behavior at subduction zones.

这项工作的主要目标是描述俯冲带沉积物的物理性质。来自南开海槽、苏门答腊海沟和阿留申海沟的沉积物实验将在德克萨斯农工大学的岩石力学实验室进行。这些实验将在高压和高温条件下进行，以模拟当一个构造板块沉入另一个构造板块之下时，沉积物被带到地球深处时遇到的条件。该项目的成果将有助于了解断层上的滑动和世界各地俯冲区发生海啸的可能性。这一项目将支持一名职业生涯早期的女研究员担任GeoPRISMS博士后研究员。这项研究旨在了解俯冲带浅层的变形行为，在那里，巨型逆冲地震破裂可能会发生更大的位移和地面变形。该项目将解决关键的基本问题，即俯冲带的浅近海沟部分是锁定的，是累积应变还是完全爬行。固结和蠕变实验将在较高的压力和温度以及不同的应变率范围内对来自三个不同俯冲系统--南开海槽、苏门答腊岛和阿留申俯冲带的沉积物样品进行。该项目的研究目标是1)表征作为压力、温度、应变率和沉积物岩性的函数的弹性、塑性和粘性变形行为，以及2)评估俯冲带浅层近海沟地区应变累积和同震滑动破裂传播的可能性。该项目将促进对俯冲带应变积累、断层耦合和滑动行为的了解。