Fault deformation dynamics along major plate boundaries

沿主要板块边界的断层变形动力学

• 批准号: 418338-2012
• 负责人: Liu, Yajing
• 金额: $ 2.26万
• 依托单位: McGill University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=634069
• 关键词: Fault; deformation; dynamics; along; major

This research program seeks to understand the physical mechanisms by which tectonic faults slide in dynamic and steady phases and their potential interactions, particularly in light of new discoveries of a spectrum of deformation modes along major plate boundaries in the past decade. The proposed work will primarily involve developing new fault dynamics models that incorporate relevant mechanisms governing fault strength, and complemented by collecting and analyzing seismic data from plate boundaries of interest.The short-term research projects will focus on two tectonic settings, representative of two end-member scenarios of earthquake cycles along plate boundaries. The first is the Cascadia margin in Pacific Northwest, which is a subduction zone capable of generating magnitude 9 earthquakes and tsunami damages every 300-600 years. The second is the Quebreda, Discovery and Gofar System of the East Pacific Rise, which are a series of mid-ocean ridge transform faults with magnitude 6 earthquakes repeating every 4-6 years. By numerically simulating the crustal deformation and comparing to seismic and geodetic observations, we will address the physical origins of episodic slow slip events and tremors, and their interaction with major earthquakes.This research will make fundamental contributions to our understanding of dynamic and slow fault slip behavior along major tectonic boundaries, and quantitative relationships between rock friction, hydrothermal transport and crustal deformation. The results will improve our earthquake forecast ability and hazard assessment. The new fault dynamics models can be potentially adapted to a broader range of environments, including continental faults and ice sheet deformation in glaciated regions.

该研究计划旨在了解构造断层在动态和稳定阶段滑动的物理机制及其潜在的相互作用，特别是在过去十年中沿着沿着主要板块边界的变形模式谱的新发现。拟议的工作将主要涉及开发新的断层动力学模型，其中纳入了控制断层强度的相关机制，并通过收集和分析感兴趣的板块边界的地震数据来补充。短期研究项目将重点关注两种构造背景，代表地震周期的两个端元场景沿着板块边界。第一个是太平洋西北部的卡斯卡迪亚边缘，这是一个俯冲带，每300-600年就能产生9级地震和海啸破坏。第二个是东太平洋海隆的Quebreda、Discovery和Gofar系统，这是一系列洋中脊转换断层，每4-6年重复一次6级地震。通过对地壳形变的数值模拟，并与地震和大地测量观测结果进行对比，探讨幕式慢滑事件和地震的物理成因及其与大地震的相互作用，为我们理解沿着主要构造边界的动态和慢断层滑动行为，以及岩石摩擦、热液运移与地壳形变之间的定量关系做出基础性贡献。研究结果将有助于提高我国地震预报能力和灾害评估水平。新的断层动力学模型可能适用于更广泛的环境，包括大陆断层和冰川地区的冰盖变形。