Reservoir construction from the Newberry Volcano EGS Demonstration

On the Potential Role of Viscoelasticity in Fluid‐Induced Seismicity

“…This behavior translates into an approximate range of 1 < b < 3.5 in the Gutenberg‐Richter distribution, which is consistent with the b ‐values measured from the fluid‐induced seismic activity (Karimi & Davidsen, 2021, 2023; Kwiatek et al., 2015; Salvage & Eaton, 2021; van der Elst et al., 2016) suggesting that the heterogeneity in the yielding thresholds is responsible for the changes in the b ‐value. Furthermore, considering the Newberry EGS catalog from 2012 (Cladouhos et al., 2013) as a specific example of an isolated injection site away from any known large fault system, its b ‐value of 1.1 translates to λ = 1.75 in our model (see Section 3.1), which is obtained for s max = 1.9 (Figure 1b). The dimensionless ratio of the yielding thresholds in this case, $$\frac{{s}_{\max }-{s}_{\min }}{{s}_{\min }}$$, is ∼0.40.…”

“…This behavior translates into an approximate range of 1 < b < 3.5 in the Gutenberg-Richter distribution, which is consistent with the b-values measured from the fluid-induced seismic activity (Karimi & Davidsen, 2021, 2023Kwiatek et al, 2015;Salvage & Eaton, 2021;van der Elst et al, 2016) suggesting that the heterogeneity in the yielding thresholds is responsible for the changes in the b-value. Furthermore, considering the Newberry EGS catalog from 2012 (Cladouhos et al, 2013) as a The impact of increasing the injection rate from (a) 〈I〉 = 10 −3 to (d) 〈I〉 = 10 3 on the detectability of aftershocks using the event-event triggering analysis for model simulations with n = 3, β = 0, and s max = 2. The yellow line (obtained from shuffled catalogs) acts as a boundary, separating two distinct populations: triggered events or aftershocks below the line, and background events above the line.…”

“…The dimensionless ratio of the yielding thresholds in this case, $$\frac{{s}_{\max }-{s}_{\min }}{{s}_{\min }}$$, is ∼0.40. Given that the maximum vertical and horizontal stresses are only marginally different in Newberry ( S v ≈ S Hmax ) (Cladouhos et al., 2013), one can argue that $$\frac{{S}_{\mathit{Hmax}}-{S}_{\mathit{hmin}}}{{S}_{\mathit{hmin}}}$$ is an upper limit—if not even a reasonable proxy—of the heterogeneity of the yielding thresholds. Indeed, we find $$\frac{{S}_{\mathit{Hmax}}-{S}_{\mathit{hmin}}}{{S}_{\mathit{hmin}}}\approx 0.45$$ for Newberry, slightly larger but comparable with $$\frac{{s}_{\max }-{s}_{\min }}{{s}_{\min }}\approx 0.4$$ in our model.…”