SGER: Response of Alum Rock springs to the magnitude 5.6 Alum Rock earthquake on October 30, 2007

对地震的水文反应，如蒸汽流量增加或水井水位变化，并不少见。水文响应很重要，因为它们提供了在空间和时间尺度上很难研究的水文和构造过程的耦合的独特洞察。地震的水文响应的起源一直是有争议的主题，很大程度上是因为有许多模型来解释观测结果，而几乎没有适合区分假说的测量方法。2007年10月30日，加利福尼亚州铝石泉附近发生5.6级地震。PI对这些泉水进行了过去5年的监测，以便为地震后流量和水成分的变化提供基准。在地震后的头5天里，他记录的排泄量增加了三倍。明矾岩泉沿着海沃德断层的一条线泄流。他们排放的水是当地大气水和从深处排出的伴生水的混合物。PI将使用地震后三个月内收集的水样的稳定同位素分析，以测试所提出的流量增加的来源模型。由于每个泉水的地球化学性质是不同的，所以记录断层带管道的变化应该是可能的。也将有可能确定从泉水中流出的多余水的来源是来自深层，还是来自浅层地下。这个项目提供了一个跨学科的机会来了解断裂带的结构和演化。特别是，它将对流体在断裂带过程中的作用提供新的(可能是唯一的)限制。PI将把对泉水的监测与加州大学伯克利分校教授的课程结合起来，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。结果还将与泉水所在的明明岩公园的管理人员进行沟通。该公园是当地居民和K-12学生实地考察的热门目的地。泉水是公园的主要吸引力，这项工作可以用来更新解说标志和展示。

Hydrologic responses to earthquakes, such as increases in steam flow or changes in the water level in wells, are not uncommon. 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 almost no measurements suitable for distinguishing between hypotheses. On October 30, 2007 a magnitude 5.6 earthquake occurred near the Alum Rock springs, California. The PI monitoring these springs for the past 5 years in order to provide a benchmark for post-seismic changes in discharge and water composition. Over the first 5 days following the earthquake he documented a three-fold increase in discharge. The Alum Rock springs discharge along one strand of the Hayward fault. They discharge water that is a mixture of local meteoric water and connate waters expelled from depth.The PI will use stable isotope analyses of water samples collected over a 3 month time period following the earthquake in order to test proposed models for the origin of the increased discharge. Because the spring water at each spring is geochemically distinct it should be possible to document changes in fault zone plumbing. It will also be possible to determine whether the source of the excess water flowing from the springs originates at depth, or in the shallow subsurface. This project offers an interdisciplinary opportunity to understand fault zone structure and evolution. In particular it will provide new (and probably unique) constraints on the role of fluids in fault zone processes. The PI will integrate the monitoring of the springs with courses taught at UC Berkeley, including freshman seminars, undergraduate-level geodynamics, and graduate level classes. The results will also be communicated with the managers of Alum Rock Park where the springs are located. The park is a popular destination for local residents and K-12 student field trips. The springs are the main draw of the park and this work can be used to update interpretative signs and displays.