TRULY EXTENDED EARTHQUAKE RUPTURE

ended

We live on an active planet enveloped by ever shifting tectonic plates. The strain induced by these movements is accommodated by faults – thin zones of highly localized shear deformation. Faults deform, interact and fail via multiple physical processes (brittle, plastic, viscous) and across extremely large spatial (<1mm to >100km) and temporal (<0.001s to >10.000yr) scales. While increasingly dense observational networks and advanced laboratory experiments reveal a broad range of fault slip behaviour, the most useful thing seismologists could do - predict earthquakes – remains what we are least able to. The aim of TEAR is to comprehensively study, for the first time, the full complexity of fault system behaviour throughout the seismic cycle revealing how faults slip. Truly multi-scale and multi-physics computational models are validated against laboratory friction experiments, dense fault zone observations and analysis of induced seismicity. Conventionally, earthquakes are modelled as displacement discontinuity across a simplified surface of zero thickness based on linear elastodynamics. In contrast, TEAR will harness novel continuum phase-field theory and cutting-edge numerical techniques to develop, verify and validate a generalized visco-elasto-plastic framework including 1) visco-elastic rheologies suitable for short and long time scales, 2) spatial discretizations which capture localization phenomena (fault evolution), 3) time integrators which adapt dynamically to capture seismic events, 4) scalable high performance computing software to enable high resolution 3D simulations. By utilizing the extensive experience of the PI in earthquake modelling and high-performance computing, including the management of large-scale infrastructural projects, TEAR will not only fundamentally renew our understanding of fault slip and fault zone evolution, but provide key tools for the fast, reliable, efficient and physics-based seismic hazard assessment of the future.