Fault step-over rheology and its effect on earthquake rupture propagation

摘要

We study the effects that damage and porosity may have on rupture propagation by reducing material strength and increasing both on-fault and off-fault dissipation of earthquake energy within the step-over zone. We find that the presence of damage and porosity in step-over zones significantly reduce the width of step-overs that may be considered as rupture barriers, and therefore greatly increases fault-system stability. The results are of practical importance to seismic hazard analysis where probable length of rupture and earthquake magnitude are estimated based on mapped active faults. The results portray the importance of assessing the material state and characteristics of fault step-over zones, rather than only the general geometry of the step-over.