Topical Issues in Hydrogeology of Seismogenic Fault Zones

Abstract—The hydrogeology of fault zones, especially at considerable depth, is perhaps a most underdeveloped field in earthquake source mechanics. This is due to both the lack of the data on the filtration characteristics of the geomaterial at large depths and to the complexity of the processes of mass transfer, fracture formation and healing under high temperatures and pressures. In this case, the strong influence of fluid on both the friction characteristics and the stress conditions in the vicinity of the slip zone is obvious. Fluids are carriers of dissolved matter and thermal energy, an effective catalyst for various types of metamorphic transformations. According to some models, fluid flows can be triggers for the initiation and arrest of seismogenic ruptures. The current trend in world seismology to constructing a complex computational model that adequately describes the processes of preparation, initiation, and arrest of various fault slip modes requires developing the ideas about fluid dynamics of seismogenic faults. This review considers the information on hydrogeology of fault zones obtained in recent years. Models and ideas involving field data, laboratory and field experiments and numerical calculations regarding the role of fluids at different stages of the seismic cycle are analyzed.