Earthquake Triggering and Synchronization on Oceanic Transform Faults

当走滑断层在人口中心附近破裂时，可能会造成重大破坏。虽然沿着单一断层链滑动的基本机制相对较好地理解，但在历史活动带内的多股断层的行为可能是复杂的。通过研究两种类型的断层系统活动，可以在定量和预测了解断层行为方面取得进展：1)地震触发--遥远的地震触发局部断层上的滑动；2)地震同步--在给定断裂带的许多地震周期中，两次大地震在时间和空间上接近地发生。大洋转换断层构造背景简单，地震周期相对较短，是研究这类行为的理想方法。这项研究有助于在新的大学职位上建立一个年轻的研究员，使他能够将他的专业知识扩展到海底断层，并为本科生提供培训。海洋转换断层的地震触发调查利用了这些系统的加载和破裂的短周期(约20年)。覆盖范围很小，但海底地震仪、水听器、浮标和近岸陆地地震台站的组合确实提供了数据。将搜索地震目录，以寻找与大型远震地震波的传播相对应的事件，或者表明区域同步活动的事件，这表明事件是由断层之间的应力传递动态触发的。为了将知识从概念模型提升到定量模型，将进行包含速率和状态摩擦参数的数值模拟。一项新的发展将是将沿断层的变化包括在断层性质和演化的二维模型中。将使用来自Blanco、Quebrada-Discovery-Gofar、Romanne和Eltanin断层系统的相当详细的数据，而不是以前的工作，这些工作依赖于稀疏的远震数据来进行全球海洋转换断层行为的研究。

Strike-slip faults can cause major damage when they rupture near population centers. While the basic mechanism of slip along a single fault strand is relatively well understood, behavior of multi-strand faults within a historically active zone can be complex. Progress towards a quantitative and predictive understanding of fault behavior can be achieved by studying two types of fault system activity: 1) earthquake triggering- a distant earthquake triggers slip on a local fault; 2) earthquake synchronization- two large earthquakes occur close in time and space over many earthquake cycles on a given fault zone. Oceanic transform faults are ideal for studying such behavior because of their simple tectonic setting and relatively short earthquake cycle. This research helps establish a young researcher in a new university position, allowing him to extend his expertise to submarine faults, and it provides training for an undergraduate student.Investigation of earthquake triggering at oceanic transform faults takes advantage of the short cycle of loading and rupture (~20 yrs) for these systems. Coverage is sparse but a combination of ocean bottom seismographs, hydrophones, buoys, and near-shore land seismic stations do provide data. Earthquake catalogs will be searched for events that correspond with passage of waves from large teleseismic earthquakes or that indicate synchronous regional activity, suggesting events that are dynamically triggered by stress transfer between fault segments. In an effort to advance knowledge from conceptual to quantitative models, numerical modeling that incorporates rate and state friction parameters will be performed. A new development will be to include along-fault variations in 2-D models of fault properties and evolution. Fairly detailed data from the Blanco, Quebrada-Discovery-Gofar, Romanche and Eltanin fault systems will be employed, in contrast to previous work that depended on sparse teleseismic data for global studies of oceanic transform fault behavior.