Dynamics of Fluid Induced Aseismic Slip
Résumé
Fluid operations at depth not only trigger earthquakes but also aseismic slip on preexisting faults. In many cases the aseismic slip activates in turn a significant amount of seismicity. Understanding the dynamics of such propagating slow slip phenomena is thus of primarily importance to better assess the induced seismicity hazard. Here we model a typical aseismic fault by a planar interface between elastic half spaces, where slip is resisted by Dieterich-Ruina friction. We present numerical results about the slow slip events generated by a local fluid injection on such a fault. We demonstrate the existence of a self similar solution for slip rate along this fault of the form $V=t^{−1}f(x/t)$. This solution allows to identify the mechanical parameters controlling the evolution of slow slip in response to a localized pressure increase.