Time evolution of stress under an artificial lake and its implication for induced seismicity

Abstract

The time history of stress beneath a realistic artificial lake with a realistic loading history on a permeable lithosphere can be calculated by solving the consolidation equations for a uniform permeable medium. The evolution of stress conditions towards or away from a Mohr–Coulomb failure envelope illustrates that highest risk of induced seismicity exists at initial loading and in some cases after a down-draw of the lake. The calculated histories depend crucially on hydrologic and geologic conditions which are very poorly known at many artificial lakes. If the formation strengths are constant in the area of the lake, consolidation theory indicates that failure is most likely under the lake in strike-slip or normal fault regimes. If failure occurs due to loading on a thrust fault regime it will occur at an offset from the lake.