UNRAVELING THE SPECTRUM OF SLIP BEHAVIOR: MODELING FAULT ZONE GEOMETRICAL COMPLEXITY
In recent decades, there has been a proliferation of observations related to spatiotemporally intricate slip events occurring in fault systems. These slip events span a range of time scales, from creep and slow slip events (SSEs) detectable only through geodetic methods, to very-low-frequency earthquakes (VLFEs), low-frequency earthquakes (LFEs), tectonic tremors, and ultimately, earthquakes. At present, these events are generally interpreted by imposed frictional heterogeneities along the fault plane. However, fault systems are geometrically complex in nature over different scales. In this work we investigate the role of ”realistic” fault geometry on the dynamics of slip events. We consider a fault system in a 2D quasi-dynamic setting. The fault system consists of a main self-similar rough fault, surrounded by a dense network of off-fault fractures. We show how mechanical interaction among rate-weakening faults and the damage zone reproduces seismic activity similar to natural observed earthquake catalogues. This similarity is presented in terms of the frequency of magnitudes, the increase in seismicity rate prior to the total breakdown of the main fault, and its decrease thereafter. Additionally, our analysis of slip rates reveals a broad spectrum of rupture modes, ranging from SSEs, VLFEs, LFEs and tectonic tremors. By modeling synthetic seismic and geodetic signals, we clarify the spatiotemporal relationships among these events, shedding light on the broadband nature of slow earthquakes.