Constraining Continental Rifting Using a Novel Seismic Imaging Approach

Scott Burdick博士被授予NSF博士后奖学金，在马里兰州大学开展研究和教育计划。调查的重点将是制作裂陷大陆岩石圈和下伏地幔的地震图像，以便对控制大陆裂陷的因素提供新的限制。大陆裂谷带是发生伸展和岩石圈破裂的局部区域，在大陆演化中起着中心作用。尽管裂谷岩石圈模型的进展，有关大陆裂谷的启动和演化的基本问题仍然存在。教育计划将包括为入门课程开发教学模块，并指导研究生和本科生开发层析成像模型。为了实现该项目的目标，Burdick博士将使用全地幔走时层析成像和一种新颖的反射层析成像方法，该方法同时限制地震速度的平滑变化和地震不连续面的位置，如岩石圈-软流圈边界和中-岩石层不连续面。拟议的研究重点是两个活跃的和仪器齐全的大陆裂谷：格兰德河裂谷和索尔顿槽。为了提供一个参考点，在裂谷的启动所涉及的预先存在的地震特性，该项目还将审查南格鲁吉亚缝合线。所有研究区域都被密集的宽带地震台阵覆盖。来自这些阵列的数据以及USAray可移动阵列和全球目录将用于大陆规模的研究部分，这将有助于提供与更深层次进程的联系。

Dr. Scott Burdick has been awarded an NSF EAR Postdoctoral fellowship to carry out a research and education plan at the University of Maryland. The investigation will focus on developing seismic images of rifting continental lithosphere and the underlying mantle in order to provide new constraints on the factors that control continental rifting. Continental rift zones, localized regions where extension occurs and the lithosphere is ruptured, play a central role in continental evolution. Despite progress in modeling of rifting lithosphere, fundamental questions concerning the initiation and evolution of continental rifts remain. The education plan will include developing teaching modules for introductory classes, and mentoring graduate and undergraduate students in developing tomographic modelsTo accomplish the goals of the project, Dr. Burdick will use whole-mantle traveltime tomography and a novel reflection tomography method that simultaneously constraints both smooth variations in seismic velocity and locations of seismic discontinuities, such as the lithosphere-asthenosphere boundary and mid-lithopsheric discontinuities. The proposed research is focused on two active and well-instrumented continental rifts: the Rio Grande Rift and the Salton Trough. In order to provide a point of reference on the preexisting seismic properties involved in the initiation of rifting, the project will also examine the South Georgia Suture. All study regions are covered by dense broadband seismic arrays. Data from these arrays, as well as the USArray Transportable Array and global catalogues will be used in the continental-scale research component that will help provide a connection to deeper processes.