Generic Mechanism for Remote Triggering of Earthquakes

TL;DR

This paper proposes a generic mechanism explaining remote earthquake triggering, showing that small perturbations can cause exponential instability in stressed systems due to frictional symmetry breaking, with significant implications for understanding earthquake phenomena.

Contribution

The paper introduces a novel, generic model for remote earthquake triggering based on Hamiltonian symmetry breaking caused by friction, applicable across various systems.

Findings

Stable stressed systems are highly sensitive to small perturbations.

Small perturbations can lead to exponential growth in displacements.

Nonlinear effects can amplify displacements by 15-20 orders of magnitude.

Abstract

``Remote triggering" refers to the inducement of earthquakes by weak perturbations that emanate from far away sources, typically intense earthquakes that happen at much larger distances than their nearby aftershocks, sometimes even around the globe. Here, we propose a mechanism for this phenomenon; the proposed mechanism is generic, resulting from the breaking of Hamiltonian symmetry due to the existence of friction. We allow a transition from static to dynamic friction. {\em Linearly stable} stressed systems display giant sensitivity to small perturbations of arbitrary frequency (without a need for resonance), which trigger an instability with exponential oscillatory growth. Once nonlinear effects kick in, the blow up in mean-square displacements can reach 15-20 orders of magnitude. Analytic and numerical results of the proposed model are presented and discussed.