Earthquake statistics and plastic events in soft-glassy materials

Abstract

We propose a new approach for generating synthetic earthquakes based on the physics of soft glasses. The continuum approach produces yield-stress materials based on Lattice–Boltzmann simulations. We show that if the material is stimulated below yield stress, plastic events occur, which have strong similarities to seismic events. Based on a suitable definition of displacement in the continuum, we show that the plastic events obey a Gutenberg–Richter law with exponents similar to those for real earthquakes. We also find that the average acceleration, energy release, stress drop and interoccurrence times scale with the same exponent. Furthermore, choosing a suitable definition for aftershocks, we show that they follow Omori's law. Finally, the far field power spectra of elastic waves generated by these plastic events decay as ω−2 similar to those observed for seismic waves. Our approach is fully self-consistent and all quantities can be calculated at all scales without the need of ad hoc friction or statistical assumptions. We therefore suggest that our approach may lead to new insights into the physics connecting the micro- and macroscales of earthquakes.