Mechanical, chemical, and hydraulic interactions in hydrothermal faults

During the earthquake cycle, seismically active faults undergo a cyclical strength evolution that is closely linked to healing processes occurring on the microscale, e.g. compaction and contact welding. Understanding in detail how these time-dependent healing processes affect the strength recovery is crucial knowledge for the reliable assessment of seismic hazards. This study investigates fault healing during the interseimic period, focusing on the interplay between mechanical, chemical, and hydraulic processes. We propose to conduct deformation experiments on analogue fault gouge materials using 4D X-ray CT imaging to document dynamic feedbacks and emerging microstructures. Our approach will provide insights into microscale processes affecting fault healing, the evolution of hydraulic properties, and therefore fluid migration during active deformation. Hence, it will allow us link grain-scale healing to macroscopic fault dynamics. This research is supported through the EXCITE network.