CAREER: Investigating Earthquake Cycles on Mid-Ocean Ridge Transform Faults

University Of New Hampshire, Durham NH

Investigators

Abstract

Seismicity on mid-ocean ridge transform faults (RTFs) is remarkably systematic and this study will explore the physical reasons for this unusual predictability in earthquake behavior. Transform fault length and plate tectonic slip rate are the basis of global scaling relations that robustly estimate the size of the largest earthquake, the seismic coupling, and the repeat time of the largest earthquakes on most RTFs. However, the processes that create this regularity in RTF seismic cycles and that limit the size of their largest earthquakes are unknown. This integrated research and education project comprises two main components: A comprehensive analysis of RTF structure from high-resolution multibeam bathymetry and finite element modeling of RTFs; Derivation of earthquake source parameters on typical (Gofar) and atypical (Clipperton) RTFs to compare along strike variation in seismic coupling and fault properties. The ultimate aim of this project is to improve seismic hazard assessment by determining if time-dependent hazard models, which describe hazard as being low following a large earthquake and building with time, actually reflect the underlying mechanics of fault slip on geometrically simple faults. Part of the study will be completed through undergraduate class projects, with students trained in the use of geophysical datasets and resources. Two graduate students will gain research experience. Basic concepts on earthquake generation and predictability will be conveyed to high school physics teachers through simple analog experiments that are one component of a new professional development workshop. High school physics curricula will be developed as an outcome of the Summer workshops, and university students will gain educational experience working in the classroom with the teachers throughout the following school year.