The Role of Fluid Pressure‐Induced Aseismic Slip in Earthquake Cycle Modulation

Abstract

AbstractThe evolving state of fault stress during and after the perturbation of fluid pressure gives rise to an intriguing interplay of seismic and aseismic slip on the fault. A better understanding of the possible role of fluids in the triggering mechanism of seismicity is pivotal to effective seismic hazard mitigation, particularly in the context of induced seismicity. Through numerical modeling, we investigate the effect of pore pressure perturbations on the spatio‐temporal evolution of fault slip and the modulation of earthquake cycles. Pressure perturbations are imposed at different magnitudes and different times during a selected interseismic period. Results show a wide range of aseismic responses which can lead to both time advancement and delay of subsequent earthquakes. Specifically, even pressure perturbation <5% of the average event stress drop can trigger aseismic slip that leads to considerable time delay in the next earthquake even when perturbation occurs late in the interseismic period. We find that earthquakes that are delayed in time are associated with large aseismic moment release. Our study highlights the importance of close monitoring of aseismic fault slip in regions prone to the influence of pore fluids and provides physical insights into identifying critical aseismic responses associated with certain triggering outcomes.