EAR-PF Mapping Sharp Interfaces in Continental Rifts

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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.