Abstract
We report results from a parametric study of various weakening mechanisms that can occur in olivine aggregate materials to help understand how an episode of runaway subduction could be initiated. We use a finite element analysis employing an internal state variable plasticity/damage model to show that temperature contrasts, loading rate, crystallographic damage, water content, and initial anisotropy can all induce significant mechanical instability in olivine rock. Our results indicate that each of these weakening/localization effects may have played an important role in fashioning an initial state for the earth from which the Flood cataclysm could easily emerge.