Collaborative Research: Origin of hydrologic responses to earthquakes: constraints from New Zealand, Taiwan, Chile, and USA

地震会产生水文响应，例如河流流量增加和威尔斯水位变化。这样的水文响应是重要的，因为它们提供了独特的洞察水文和构造过程在空间和时间尺度上的耦合，否则很难研究。地震水文响应的起源一直是争议的主题，很大程度上是因为有许多模型来解释观测结果，而很少有测量方法适合区分假设。我们将研究新西兰、智利、台湾和加州对地震的反应，通过1）汇编观测结果，2）收集新的测量结果，3）开发分析和数值模型来解释水文和相关的大地测量数据，以检验相互竞争的假设。我们将讨论以下问题：河流中的过量排放是源于浅层还是深层地下？深层和地下水系统的反应有何不同？岩石和松散材料是否有不同的、可理解的反应？地下的性质（如渗透率）是否有永久性变化？对于解释观测到的变化，静态应力和动态应力哪个更重要？该项目提供了一个跨学科的培训机会，整合了地球物理学和水文学，并结合建模和实地研究。这项拟议中的工作是与台湾、德国和新西兰科学家的国际合作。我们将把拟议的研究与加州大学伯克利分校的课程相结合，包括新生研讨会，本科生水平的地球动力学和研究生水平的课程。对地震引起的水文变化的研究对水资源和工程有影响，包括评估地震在破坏含水层、影响地下蓄水库和改变供水方面的作用。

Earthquakes generate hydrological responses, such as increases in stream flow and changes in the water level in wells. Such hydrologic responses are important because they provide unique insight into the coupling of hydrologic and tectonic processes at spatial and temporal scales that are otherwise difficult to study. The origin of hydrologic responses to earthquakes has been the subject of controversy, in large part because there are many models to explain observations and few measurements suitable for distinguishing between hypotheses. We will study responses to earthquakes in New Zealand, Chile, Taiwan, and California to test competing hypotheses by 1) compiling observations, 2) collecting new measurements, and 3) developing analytical and numerical models to interpret the hydrological and related geodetic data. We will address the following questions: Does the excess discharge in streams originate from the shallow or deep subsurface? How do the response of deep and groundwater systems differ? Are there different and understandable responses of fracture-dominated rock and unconsolidated materials? Are there permanent changes in properties of the subsurface such as permeability? Are static or dynamic stresses more important for explaining the observed changes?This project offers an interdisciplinary training opportunity that integrates geophysics and hydrology, and combines modeling and field studies. The proposed work is an international collaboration with scientists in Taiwan, Germany and New Zealand. We will integrate the proposed research with courses taught at UC Berkeley, including freshman seminars, undergraduate-level geodynamics, and graduate level classes. The study of earthquake-induced hydrologic changes has implications for water resources and engineering, including assessing the role of earthquakes in damaging aquifers, affecting underground repositories, and changing water supplies.