CAREER: Data-Driven Inversion of Subduction Zone Topography using Tectonic Geomorphology

Colorado State University, Fort Collins CO

Investigators

Abstract

The development of Earth’s topography impacts the flux and routing of surface water, sediment, and nutrients to oceans, affects feedbacks between the solid Earth and atmosphere, and impacts the evolution and diversity of species. Earth’s topography is also a primary observable of tectonic activity. For example, nearly every Earth science student learns to identify deep ocean trenches and adjacent mountain belts as the surface expression of active subduction, where one tectonic plate dives beneath another. It follows that we should, in principle, be able to use subduction zone topography (or that of any other active orogen) to understand the underlying geodynamic processes involved in its construction. While scientists have made great strides in this direction, recovering tectonic signals directly from topography remains a crucial challenge. This research will develop and apply new methods to narrow this knowledge gap through a case study of the Calabrian subduction zone in southern Italy. This study will clarify the role of topography as a recorder of subduction zone dynamics and improve understanding of the landscape response to geodynamic forcing by disentangling crustal, mantle, and earth surface contributions to topographic change. The new methods and results will be relevant for better understanding the context of earthquake hazards along these dynamic plate boundaries. Through a three-pronged educational outreach program, this project will engage traditionally underrepresented groups in primary research, develop community education modules, and host workshops to train professionals to use the scientific and educational materials developed. This study will conduct a plate boundary-scale paleo-geodetic experiment realized through the development and application of a novel data-driven Bayesian inversion of tectonic geomorphology measurements and fluvial topography. This approach will be used to test the hypothesis that the recent and rapid rise of topography above the Calabrian subduction zone is driven by mantle dynamics associated with slab tearing and asthenospheric flow around torn slab edges. This study will compile existing and generate new datasets on long-term erosion rates, the magnitude and age of uplifted marine and river terraces, and fault slip and kinematics. This project will train two Ph.D. students and three undergraduates through participation in field and lab work, data analysis, modeling, outreach, writing, and national conferences. The integrated education plan will focus on three related components: (1) an undergraduate training network (UTN), (2) development of community educational resources, and (3) targeted outreach and training. The UTN will recruit three undergraduate students, emphasizing those from underrepresented groups, to participate in a multi-year program to foster the development of next-generation leaders in Earth science through participation in research and outreach. Working with experts at the Geodesy Tools for Societal Issues (GETSI) program and Science Education Research Center (SERC), community educational resources developed will focus on field geodesy and tectonic geomorphology techniques and datasets generated during this study. Outreach and training of the generated scientific and educational materials will be bolstered through participation in GETSI-sponsored outreach and the hosting of workshops at national conferences. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.