As urban populations grow, destructive natural earthquakes pose an increasing threat in tectonically active regions. At the same time, seismicity caused by geo-resource extraction, geological storage and other subsurface activities is becoming increasingly widespread. The need to improve our understanding of faulting and seismogenesis is therefore reaching new levels of urgency. Yet these phenomena involve some of the most complex and highly coupled thermo-hydro-mechanical–chemical (THMC) processes imaginable. The initiation, propagation and cessation of slip instabilities on faults, for example, embody damage accumulation, frictional deformation, heat production, pore fluid pressurization, phase changes, chemical reactions, creep and reactive fluid flow at multiple temporal and spatial scales. Advances that contribute to earthquake hazard assessment and mitigation depend on integrating different research fields and disciplines to address such processes and their coupling.

This special issue aims to collect studies that consider THMC processes in earthquake and faulting mechanics building on insights from laboratory and computational experiments and from induced and natural seismicity.