Rogue serpentinite-breakdown waves: a source mechanism for major subduction earthquakes?

Abstract Episodic tremor and slip (ETS) in subduction megathrusts can accommodate plate motion in a silent manner without major damage. Yet, sometimes fast slip events seem to occur just prior to a large earthquake such as observed in New Zealand. Here, we show that the ETS and earthquake mechanisms can trigger each other in a two-way coupled manner due to the entanglement of fluid reactions and solid deformation within the slip zone. We propose that large earthquakes form as slab-wide network forming fluid-release events synchronising through nonlinear ultra-focusing excitation waves of the rogue-wave type. The generality of this approach renders it applicable to the nominally aseismic Cascadia subduction zone where the largest magnitude 9 event occurred 315 years ago.