The emergence of seismic cycles from stress feedback between intra-plate faulting and far-field tectonic loading

초록

Using numerical modeling we show the emergence of cyclic slip behavior of faults from stress feedback through an idealized fault, its surrounding plates and far-field tectonic stress. The tectonic stress is exerted on the fault through a force applied along an idealized plate margin, acting on the fault, resulting from the interactions of viscous embedding and external plates. We find that, in such coupled system, the interaction of plates results into feedback with periodic deformation, slip along the fault and episodic plate margin motions. The viscosity of the embedding and loading plates primarily control the stress loading time and hence the slip recurrence interval. For an Earth-like range of lithospheric viscosities, we derive a power-law with negative exponent, 0.99 to 0.5, scaling the recurrence period with loading rate, providing an explanation for the observables from paleoseismology and geodesy. The feedback between single fault and far-field stress that arises from interactions of deforming plates provides a context to understand the earthquake cycle within continents, while reconciling the short-term seismic deformation to the long-term plate tectonics frame. (C) 2016 Elsevier B.V. All rights reserved.

키워드