Maximum size and magnitude of injection-induced slow slip events

TL;DR

This paper develops scaling relations to estimate the maximum size and magnitude of injection-induced slow slip events, integrating rupture physics and fluid injection histories, and validates predictions with diverse observational data.

Contribution

It introduces new theoretical scaling relations for maximum aseismic rupture size and magnitude considering fluid injection parameters and stress conditions.

Findings

Predictions align with laboratory and real-world observations.

Fault-zone storativity and fluid volume are key determinants.

Maximum slip magnitude can be constrained by derived scaling laws.

Abstract

Fluid injections can induce aseismic slip, resulting in stress changes that may propagate faster than pore pressure diffusion, potentially triggering seismicity at significant distances from injection wells. Constraining the maximum extent of these aseismic ruptures is thus important for better delineating the influence zone of injections concerning their seismic hazard. Here we derive a scaling relation based on rupture physics for the maximum size of aseismic ruptures, accounting for fluid injections with arbitrary flow rate histories. Moreover, based on mounting evidence that the moment release during these operations is often predominantly aseismic, we derive a scaling relation for the maximum magnitude of aseismic slip events. Our theoretical predictions are consistent with observations over a broad spectrum of event sizes, from laboratory to real-world cases, indicating that fault-zone storativity, background stress state, and injected fluid volume are key determinants of the maximum size and magnitude of injection-induced slow slip events.