Triggered tremor, phase-locking, and the global clustering of great earthquakes

Abstract

A system of non-linear coupled relaxation oscillators is used to show how the communication between large earthquakes on a global scale can align their seismic cycles to produce a worldwide clustering of large events. Our model builds on recent observations that the seismic waves from a large earthquake can trigger an episode of non-volcanic tremor at the base of a distant fault. We assume that tremor is indicative of creep on the ductile extension of the fault zone that loads its overlying seismogenic layer thus advancing the fault toward failure. If this advance is larger toward the end of the seismic cycle, we show that two or more interacting faults will align their cycles, even if their recurrence intervals are not identical.