Time‐dependent compaction as a mechanism for regular stick‐slips

Abstract

Owing to their destructive potential, earthquakes receive considerable attention from laboratory studies. In friction experiments, stick‐slips are studied as the laboratory equivalent of natural earthquakes, and numerous attempts have been made to simulate stick‐slips numerically using the Discrete Element Method (DEM). However, while laboratory stick‐slips commonly exhibit regular stress drops and recurrence times, stick‐slips generated in DEM simulations are highly irregular. This discrepancy highlights a gap in our understanding of stick‐slip mechanics, which propagates into our understanding of earthquakes. In this work, we show that regular stick‐slips emerge in DEM when time‐dependent compaction by pressure solution is considered. We further show that the stress drop and recurrence time of stick‐slips is directly controlled by the kinetics of pressure solution. Since compaction is known to operate in faults, this mechanism for frictional instabilities directly relates to natural seismicity.