A-seismic fracture growth driven by fluid injection and remote nucleation of dynamic rupture in a weaker part of the fault

Induced (and triggered) seismicity following fluid injections at depth, is governed by pore pressure diffusion. Interestingly, recent studies yield unrealistically large values of diffusivity in order to explain the timing of the generated seismicity. We investigate here the possibility of induced (or rather triggered) seismicity due to stress transfert at some distance along the fault from the injection point (hereafter called remote nucleation/activation). We restrict our discussion to the case of pressurization from a point on the fault in a friction neutral zone. We discuss how a-seismic slip induced by fluid injection can generate stress transfert in a frictionally weakening zone, located at some distance from the injection point. For typical stress and pore-pressure regimes at depth, we discuss the key parameters controlling the possible occurrence of seismicity at a finite distance from an aseismically growing "mother crack". Finally, we seek to name the conditions under which the aseismically growing "daughter crack" could show a dynamic nucleation.