The role of effective normal stress, frictional properties, and convergence rates in characteristics of simulated slow slip events

Abstract

AbstractSlow slip events (SSEs) observed in subduction zones around the world exhibit a wide range of recurrence intervals, durations, and propagation speeds. To illuminate possible mechanisms responsible for the observed variability and guide future modeling efforts, we employ the earthquake simulator RSQSim to explore the effects of variations in the convergence rates, frictional parameters, and effective normal stress on SSE characteristics. Both recurrence intervals and durations of SSEs are essentially directly proportional to the effective normal stress, while along‐strike propagation speeds are inversely proportional. Effective normal stresses in the range of 3–9 MPa produce fault slip consistent with observed SSEs. Changes in rate‐state frictional instability (b − a) have a moderate inverse effect on propagation speeds but much weaker effects on recurrence intervals and durations. Convergence rates are inversely proportional to recurrence intervals, propagation speeds show a weak positive relationship, and event durations appear insensitive.