EAR-PF Mapping Sharp Interfaces in Continental Rifts

Ved Lekic博士获得了美国国家科学基金会地球科学博士后奖学金，在布朗大学开展研究和教育计划。他将研究大陆裂谷的原因和机制，这是大陆撕裂和新板块边界形成的过程。该项目将重点关注三个活跃的大陆裂谷，它们跨越了不同的速度、几何形状和扩展量、不同的成熟度和地球化学特征：里约热内卢大裂谷、萨尔顿海槽以及东非裂谷的埃塞俄比亚和肯尼亚部分。地震数据分析（接收函数、层析成像和正演波形建模分析）将用于同时绘制广泛的软流圈和岩石圈特征，以及探测和表征尖锐的界面，如地壳-地幔边界、岩石圈-软流圈边界和其他可能与熔融或断裂有关的特征。对不同年龄、成熟度、地球化学特征和变形参数的活动大陆裂谷相关的水平和陡倾界面进行制图和表征，将有助于揭示裂谷作用的成因、机制和演化。在过去的四十年里，板块构造理论极大地增强了我们对地球如何运行的理解。然而，我们仍然远远不能理解构造板块最初是如何形成的，以及大陆是如何在被称为大陆裂谷的位置分裂成多个板块的。这次调查将产生大陆裂谷内部结构的图像，这些图像可以用来了解大陆板块削弱和分裂的过程，以及地球深处所起的作用。因此，它可以阐明板块构造是如何产生的以及它是如何继续运作的。教育部分将以两门课程为中心：一门由Lekic和东道主导师共同教授的高级研讨会，以及一门由Lekic和东道主机构的一名教员共同教授的地球物理学入门课程。高级研讨会的重点是大陆岩石圈的结构、流变学和动力学，将直接纳入研究提出的问题和提供的见解。它还将提供一个跨学科的场所，来自不同地球科学背景的教授、博士后研究人员、研究生和高级本科生可以在这里学习和讨论重大问题和最新发现。本科课程将允许Lekic开发，应用和评估一套积极的学习技巧，并使他能够尝试各种活动和方法，以吸引学生的不同学习风格。

Dr. Ved Lekic has been granted the NSF Earth Sciences postdoctoral fellowship to carry out a research and education plan at Brown University. He will investigate the causes and mechanics of continental rifting, which is the process in which continents are torn apart and new plate boundaries form. The project will focus on three active continental rifts that span a variety of rates, geometries and amounts of extension, different maturity and geochemical signatures: the Rio Grande Rift, the Salton Trough, and the Ethiopian and Kenyan segments of the East African Rift. Analysis of seismic data (receiver function, tomographic, and forward waveform-modeling analyses) will be used to simultaneously map broad asthenospheric and lithospheric features as well as detect and characterize sharp interfaces such as the crust-mantle boundary, the lithosphere-asthenosphere boundary, and other features that may be related to melting or faulting. Mapping and characterizing horizontal and steeply dipping interfaces associated with active continental rifts of different age, maturity, geochemical signature and deformation parameters will shed light on the causes, mechanics and evolution of rifting. In the last four decades, the plate tectonic paradigm has tremendously enhanced our understanding of how our planet works. Yet, we are still far from understanding how tectonic plates formed in the first place and how continents can break up among multiple plates at locations known as continental rifts. This investigation will create images of structures within continental rifts that can be used to learn about the processes by which continental plates weaken and break apart and the role that Earth's deep interior plays. As such, it may elucidate the way plate tectonics arose and how it continued to operate. The educational component will be centered on two courses: an advanced seminar co-taught by Lekic and the host mentor, and an introductory course in geophysics co-taught by Lekic and a faculty member at the host institution. The advanced seminar, focused on the structure, rheology and dynamics of the continental lithosphere, will directly incorporate the questions raised and insights provided by the research. It will also provide an interdisciplinary venue in which professors, post-doctoral researchers, graduate students, and advanced undergraduates from a variety of geoscience backgrounds can learn and discuss major questions and latest findings. The undergraduate course will allow Lekic to develop, apply and evaluate a suite of active learning techniques and enable him to experiment with activities and approaches that engaging the students' diverse learning styles.