CAREER: Seismic Imaging of Large-Scale Structure in the Lithosphere and the Core-Mantle Boundary Region

University Of Maryland, College Park, College Park MD

Investigators

Abstract

I propose to obtain new constraints on the structure of the continental lithosphere and the core-mantle boundary region, with the goal of improving our understanding of the formation, evolution, and preservation of large-scale structures within the mantle. Accomplishing this goal will require improving on existing and developing new methods for modeling and analyzing seismic waveforms, and will have implications for the understanding of the dynamics of the Earth's deep interior and its relationship to the surface. The scientific questions to be addressed are: 1. What is the nature of the mid-lithospheric discontinuity and what does it tell us about the architecture, origin, and evolution of stable continental lithosphere? 2. What processes control the development of rifts in general, and strain localization throughout the lithosphere? 3. What are the morphology, and elastic characteristics of mesoscale structures in the lowermost mantle? The improved seismic imaging methods will be built around flexible and parsimonious parameterizations that can also reproduce the various ways in which seismic waves interact with geological structures. The proposed work also includes developing automated computational algorithms for analyzing and modeling seismic data, determining optimal weighting of different datasets, and identifying new seismic observables. Alongside this research project, I propose to undertake a comprehensive educational project called SeismoABCs (Seismology Across and Beyond Classrooms), whose purpose is to improve undergraduate education and learning outcomes through the incorporation of seismological instrument deployment, data collection and analysis across the undergraduate curriculum at the Department of Geology of the University of Maryland, College Park. The proposed work will develop and apply new methods for imaging the Earth's interior using multiple seismic datasets. It will focus on providing new images of and constraining structures in two distinct settings: the continental lithosphere, which makes up the tectonic plates and controls the internal deformation in continents, and the core-mantle boundary region, which contains exotic features fundamentally related to the dynamics and thermo-chemical evolution of the Earth. The new methods developed as part of the proposed work will be broadly applicable to any discipline confronted with the problem of combining different pieces of information in order to constrain characteristics of a system or object. The SeismoABCs educational component of the proposed work will have substantial broader impacts for undergraduate education at the University of Maryland. SeismoABCs is a plan to (A) incorporate the conceptualization, design, execution, and analysis of seismological experiments across classrooms in geophysics and related sciences, and (B) to enable research experiences in seismology beyond classrooms by scaling up undergraduate participation in seismological research. The desired learning outcomes of SeismoABCs include improving student's ability to formulate clear and testable research questions / hypotheses, identify relevant seismological observations, design a geophysical network to collect calibrated observations, process and analyze data in a statistically rigorous way in order to accept or reject their research hypothesis, and engage in long term research projects. The SeismoABCs program will also furnish graduate students and postdoctoral fellows with experience in mentoring students and designing and implementing a research plan. Finally, the undergraduate seismological laboratory research experiences implemented as part of this program will be targeted toward first and second year undergraduate students, and will help improve their academic achievement across STEM disciplines by providing them with real-world applications of the quantitative methods taught in the classroom setting.