EAR-PF: Structure of the North American craton from joint inversion of receiver functions, body waves, and surface waves

罗伯特·波利特（Robert Porritt）获得了美国国家科学基金会地球科学博士后奖学金，将在南加州大学开展一项研究和教育计划。他将通过地震成像方法研究北美克拉通的内部结构。该项目旨在圈定大陆岩石圈的亚水平分层，这将指示克拉通的形成是由海洋岩石圈的先后叠加而成。为了实现这一目标，接收函数、面波和体波成像技术将在一个一致的联合反演框架中结合在一起。这三种方法具有互补的灵敏度，这样，当一种方法是模糊的；另外两个提供了独特的约束。联合反演将约束速度结构并突出内层。该项目将首先对克拉通中心的哈德逊湾地区进行成像，然后利用USArray of EarthScope将其扩展到美国本土。长期大陆地壳的形成机制是地球科学中一个突出的基本问题。地震波速度模型为放置地球化学观测、启动地球动力学模型提供了必要的物理约束，并且可以与其他地球物理观测进行比较。为了促进这项跨学科的工作，通过这项工作产生的模型将随时可供公众和其他研究人员使用。该奖学金的教育部门包括研究生和本科生两个层面的内容。有竞争力的实习生建议将提交给IRIS实习和SCEC实习项目，以将热情的本科生与项目配对。额外的本科生外展活动将包括与南加州大学在摩洛哥的实地课程互动。研究生级别的部分是通过USArray短期课程，该课程汇集了来自世界各地的研究生，通过EarthScope及其USArray组件生成的不可克服的数据集传播地震数据处理的想法和最佳实践。

Robert Porritt has been granted an NSF Earth Sciences postdoctoral fellowship to carry out a research and education plan at the University of Southern California. He will study the internal structure of the North American Craton through seismic imaging methods. The project aims to delineate sub-horizontal layering in the continental lithosphere, which would indicate formation of the craton by successively stacking oceanic lithosphere. To accomplish this, receiver function, surface wave, and body wave imaging techniques will be brought together in a consistent joint inversion framework. The three methods have complementary sensitivities such that where one method is ambiguous; the other two provide unique constraints. Together, the joint inversion will constrain velocity structure and highlight internal layers. The project will start by imaging the Hudson's Bay region at the heart of the craton and then will expand to include the contiguous United States by utilizing the USArray of EarthScope. The mechanism of creating long standing continental crust is an outstanding fundamental question in earth science. Seismic wavespeed models provide physical constraints necessary for placing geochemical observations, initiating geodynamic models, and can be compared with other geophysical observations. To facilitate this cross-disciplinary work, the models generated through this work will be readily available to the public and other researchers. The education arm of the fellowship contains elements at both the graduate and undergraduate level. Competitive proposals for interns will be submitted to the IRIS Internship and SCEC Internship programs to pair enthusiastic undergraduates with the project. Additional undergraduate outreach will include interaction with a USC field course in Morocco. The graduate level component is through the USArray short course, which brings together graduate students from across the globe to spread ideas and best practices for seismic data processing with the insurmountable dataset being generated by EarthScope and its USArray component.