Hydraulic Forcing and Fault-Network State Govern Injection-Induced Rupture Cascades

Zhengze Li, & Sylvain D. Barbot

Submitted August 30, 2026, SCEC Contribution #15291, 2026 SCEC Annual Meeting Poster #009

Subsurface fluid injection enables wastewater disposal, geoenergy development, and geological storage but can trigger damaging earthquakes. Why some induced instabilities remain localized whereas others escalate into multi-fault rupture cascades remains poorly understood. We couple heterogeneous pore-pressure diffusion, rate-and-state friction, effective fault-zone poroelastic feedback, and elastic interactions in an observation-constrained model of the 2011 Prague, Oklahoma sequence. The model reproduces the three-fault rupture order, approximately 18-year injection-to-nucleation time, one- and two-day interevent delays, approximate magnitudes, and rupture extents, including the third event on an unfavorably oriented fault. It resolves a transition from injection-driven weakening of the first fault to rupture-driven stress transfer across the network. Sensitivity experiments show that hydraulic diffusivity changes nucleation timing and the first nucleating fault. Across best-matching prestress-adjusted realizations, effective poroelastic coupling controls rupture transfer across a mechanically unfavorable fault. Operational experiments show that greater source–fault separation reduces how strongly injection advances failure relative to a model no-injection reference, while intermittency and extraction act mainly through time-averaged and net injection rates. Post-sequence experiments show that a common receiver-fault prestress increment raises network-wide susceptibility but produces fault-specific activation governed by geometry and signed elastic interactions. Together, these results provide a stage-dependent framework in which hydraulic access and fault criticality govern nucleation, effective poroelastic feedback regulates rupture transfer, and fault-network state conditions subsequent activation. Induced-earthquake hazard therefore emerges from hydraulic forcing acting on a prestressed, interacting fault system.

Key Words
Induced seismicity; Poroelastic coupling; Fault-network dynamics

Citation
Li, Z., & Barbot, S. D. (2026, 08). Hydraulic Forcing and Fault-Network State Govern Injection-Induced Rupture Cascades. Poster Presentation at 2026 SCEC Annual Meeting.

Related Projects & Working Groups
Fault and Rupture Mechanics (FARM)