Seismic swarms produced by rapid fluid injection into a low permeability laboratory fault

The Role of Background Stress State in Fluid‐Induced Aseismic Slip and Dynamic Rupture on a 3‐m Laboratory Fault

“…During all experiments the top, bottom, and sides ( z = 0 m, z = 0.3 m, x = 0 m, and x = 3.1 m) of the fault interface were left open to atmospheric pressure similar to previous cm‐to m‐scale laboratory experiments (Cebry & McLaskey, 2021; Gori et al., 2021; Lockner et al., 1982), since common methods of jacketing and adding confining pressure are not feasible for 3 m long samples.…”

“…Rutter and Hackston (2017) compared experiments performed with high and low bulk permeability samples and found that low permeability samples deviated from effective stress law and required overpressure to initiate slip. Cebry and McLaskey (2021) injected fluid into a 760 mm‐long plastic sample that was larger than $${h}^{{}^{\ast }}$$ and found that the speed of induced slip (slow and aseismic vs. fast and seismic) and the number of small seismic events increased with increasing normal stress and injection rate. Gori et al.…”

High‐Rate Fluid Injection Reduces the Nucleation Length of Laboratory Earthquakes on Critically Stressed Faults in Granite

“…Fault reactivation induced by local fluid pressure perturbation has been reported over a wide range of spatial scales from lab (centimeters to meters), mine (decameters) to reservoir (kilometers) faults. In laboratory samples, fault slip induced by elevated and heterogeneous fluid pressure has been studied by regulating the injection rate, the prestresses applied to faults, and fault roughness (Cebry & McLaskey, 2021; Gori et al., 2021; Ji & Wu, 2020; Passelègue et al., 2018). Local fluid pressure perturbations due to fluid injection may directly induce aseismic slow slip, and then trigger seismic events, as has been observed for the induced seismic slip of a carbonate fault zone at mine scale in the Low Noise Underground Laboratory in France (Cappa et al., 2018, 2019; Guglielmi et al., 2015), and the 2016 M w 4.1 earthquake initiated in the Duvernay shale's caprock at field scale in Canada (Eyre et al., 2019).…”

Creep fronts and complexity in laboratory earthquake sequences illuminate delayed earthquake triggering

“…The sample was loaded in a direct shear biaxial apparatus shown schematically in Fig. 1a and used in previous studies 65 , 66 . Hydraulic cylinders C2-C5 (Fig.…”