Seismic Strain Metrics for Tracking Fault Damage Evolution and Rupture Potential in Anthropogenic Seismicity

Abstract Human-induced earthquake is an important topic for its devastating damage impact. The laboratory experiments and observational studies indicate that strong earthquakes are often preceded by a sustained period of widespread volumetric deformation. This deformation may lead to progressive shear localization, resulting in major instabilities along rupture spanning the entire system. The significant challenge is to identify measurable indicators of seismic activity that can precisely determine the progression of deformation within a rockmass or fault system. Combining insights from fracture mechanics with observations from laboratory experiments and anthropogenic seismicity, we identify key parameters that track the evolution of seismic process, relating their values to a five-step rockmass damage model. These parameters, calculated for each stage of damage, enable assessment of the current damage stage, providing insight into the preparatory stages leading to major seismic events. Using the acoustic emission data, we identify proxies for stress and damage through seismic strain dynamics metric and clustering in patterns of rupture steps. We applied this model to analyze ten significant earthquakes associated with reservoir impoundment, mining, and geothermal energy production. Our results show that accelerated seismic deformation consistently precedes these events, highlighted by a distinct clustering pattern that suggests progressive localized damage. The duration of the final damage stage extends with increasing earthquake magnitude. We also discern two dynamic regimes in the patterns of earthquake parameters, distinguished by their fracture growth dynamics: a faster mode associated mainly with mining activities and a slower mode tied to fluid-related cases. This understanding enables targeted technological adjustments to mitigate earthquake risks in geo-energy projects.