Ordinary and Slow Earthquakes Reproduced in a Simple Continuum System With Stochastic Temporal Stress Fluctuations

Abstract

AbstractEarthquakes are complex and diverse, ranging from energetic and destructive megathrust earthquakes to slow earthquakes. Complex earthquake rupture processes are generally modeled by prescribing a deterministic system and solving deterministic differential equations. However, such approaches cannot adequately capture the temporal evolution of a complex fault system because of the inherent unpredictability that results from various unprescribed processes. Such unpredictability may be better represented by time‐dependent stochastic fluctuations in addition to the deterministic estimates. Here, we demonstrate that the consideration of time‐dependent stochastic stress fluctuations in ordinary crack simulations can reproduce a variety of ruptures, including both crack‐like and pulse‐like ordinary (fast) earthquakes and slow earthquakes, by simply changing the strength drop and the initial stress level. The results indicate that stochasticity is effective for reproducing and better understanding the diversity of earthquakes, including slow earthquakes.