Fig. 1From: Cyclic soft stimulation (CSS): a new fluid injection protocol and traffic light system to mitigate seismic risks of hydraulic stimulation treatmentsMohr–Coulomb strength criterion: a driving stress (shear stress τ) and clamping stress (effective normal stress σn′ = σn − Pp) acting on a fracture and possible normal (Dn) and shear (Ds) displacements. b The failure envelope may be overcome by pore pressure increase (blue circle) or poroelastic changes in the stress field (brown circle)Back to article page