CAREER: Paleoseismicity along the North American-Caribbean Plate Boundary: Research, Education and Outreach

Missouri University Of Science And Technology, Rolla MO

Investigators

Abstract

Large intracontinental strike-slip fault systems (where one plate moves sideways against another) cut across heavily populated regions and have caused devastating earthquakes in the past. Comprehensive investigations of these fault systems are needed to understand past earthquake frequency and how these earthquakes affect fault evolution, providing crucial information to better prepare societies for future catastrophic events. This project focuses on reconstructing the earthquake history of a fault system located at the southern boundary of the North American Plate in Guatemala. The fault system is similar to the San Andreas Fault System in California, but its earthquake history remains poorly understood. By integration of geophysical methods and sedimentological investigations, this project will unravel the evolution of the fault system in time and space. The project will investigate the processes governing the frequency and location of earthquakes by examining sediments in five lakes near the fault system. In addition to the scientific outcomes, this project will provide educational opportunities for undergraduate and graduate students by training them in geophysics and sedimentology through participation in an international research project, contributing towards a stronger geoscience workforce. The project will also reach a broad public audience through the development of geoscience class modules for elementary and middle school science classes and educational geoscience workshops for K-12 science teachers. Despite continuous efforts to understand intracontinental strike-slip fault systems, several grand challenges related to the processes governing earthquake initiation, frequency, and location remain. Partly, these issues are related to the fact that historical records and instrumental measurements are insufficient to understand the long-term evolution and seismogenic behavior of fault systems, information that is paramount for seismic hazard evaluation. This project investigates the paleoseismic record preserved in five lakes in proximity to the Polochic-Motagua Fault System, the intracontinental strike-slip plate boundary fault system that separates the North American and Caribbean plates. This plate boundary setting is similar to that of the San Andreas and North Anatolian faults, but the earthquake record is largely unknown. Through seismic reflection data acquisition and characterization, and sedimentological interpretation of sediment cores, this project will contribute to the field of subaqueous quantitative paleoseismology and improve our understanding of the spatial and temporal evolution of earthquakes along this strike-slip plate boundary. The project will involve two graduate and several undergraduate students, supporting geoscience workforce development through training of geophysical and sedimentological data acquisition, processing, and interpretation. The project will also reach out to a broader audience by involving K-12 students and teachers in several educational activities, by visiting science classrooms in Missouri, by developing teacher workshops for elementary and high school teachers, and by presenting and sharing research results during STEM days for elementary and middle school female students at the Missouri University of Science and Technology. Finally, this project will provide a better foundation for assessing seismic risk along an understudied fault system in Guatemala. Involvement and collaboration with several Guatemalan higher education institutions and government agencies will facilitate international research opportunities and collaborations among U.S. and Guatemalan institutions. 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.