Fault deformation dynamics along major plate boundaries

这项研究计划试图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，特别是考虑到过去十年来沿主要板块边界的一系列变形模式的新发现。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，并辅之以从感兴趣的板块边界收集和分析地震数据。短期研究项目将侧重于两个构造背景，代表沿板块边界的地震旋回的两个终端成员情景。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。第二类是东太平洋隆起的Quebreda、Discovery和Gofar系统，是一系列大洋中脊转换断层，6级地震每4-6年重复一次。通过数值模拟地壳形变，并与地震和大地测量结果进行比较，我们将探讨幕式慢滑事件和地震的物理起源及其与大地震的相互作用。这一研究将为我们理解主要构造边界上的动态和慢断层滑动行为，以及岩石摩擦、热液输运和地壳变形之间的定量关系做出基础贡献。研究结果将提高我国的地震预报能力和危险性评估水平。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。

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.