Reconciling viscoelastic models of postseismic and interseismic deformation: Effects of viscous shear zones and finite length ruptures

摘要: We have developed a suite of earthquake cycle models for strike-slip faults to investigate how finite ruptures and lithosphere-scale viscous shear zones affect interseismic deformation. In particular, we assess whether localized stationary deformation large-scale, rapidly decaying postseismic transients may be explained with incorporating either or both these features. Models give more than layered half-space, Maxwell viscoelastic producing similar early in the near field. This tendency is accentuated when effective viscosity per unit width zone increases depth time. (200 km long) produce time-dependent that from infinitely long ruptures, though smaller-magnitude somewhat surface velocity fluctuations. stiff lithosphere, low-viscosity mantle asthenosphere, crust- can replicate typical large, earthquakes. Such require depth-dependent, power law, transient rheologies material crust, as approximately 1015 Pa s/m at crustal depths during interval. Below Moho, must higher throughout seismic cycle, least over short For example, if 5×1016 Pa s/m model 50 km thick lithosphere asthenosphere viscosities 1 5×1018 Pa s reproduce reference profiles later