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Abstract

Controlling fluid injection is widely considered a key to limiting the size of injection-induced seismicity, yet whether and how it limits earthquake size remains debated. We perform injection-reactivation experiments on critically stressed faults to test how different injection strategies shape slip and seismic moment release. We find that injection strategies regulate the cadence of slip events rather than the total seismic moment. Compared to continuous injection, cycled injection triggers frequent and smaller events, reducing maximum moment magnitude and deformation energy of individual events. Injection–extraction cycles actively reduce pore pressure, temporally partition successive slip events, and effectively suppress delayed seismicity. Regardless of constant or cycled injection rates, maximum seismic moment (M0) scales with cumulative injection volume (∆V)(i.e.,  M0 ∆V3/2). Our laboratory results suggest that regulating the cadence of moment release promotes effective hazard mitigation.