Dynamic rupture forewarned by a displacement field criterion

Abstract

Ground-surface accelerations warn of incipient natural hazards—but threshold criteria remain indistinct. We use a model of localizing deformation within a encapsulating compliant halo to accurately project time-to-failure and to discriminate between ultimate stable and unstable rupture. A heterogeneous distribution of displacement histories and relative polarities demark composite zones of local failure. These composite zones accommodate strain accumulation in the localizing core and strain-relaxation in the surround. Balanced rates of strain accumulation and complementary shedding project both a time-to-rupture and anticipated energetics—quiescent of dynamic. This analysis is applied to follow the evolution of both local discrete ruptures and their coalescence into macroscale failure—with equal resolution and success. Apparent is a typical deformation response characterized by creep, relaxation and reload at different positions.