Short‐Lived and Voluminous Fluid‐Flow in a Single Fracture Related to Seismic Events in the Middle Crust

Abstract

Abstract This study focuses on samples that underwent rapid hydration (∼10 hr) and evolved in permeability (∼10−9 to 10−8 m2) as a result of crustal fracturing. A coupled reactive transport model and thermodynamic analyses, focusing on Si alteration processes within reaction zones, are used to estimate the fluid volume required to induce fluid‐driven seismic activity. Estimated fluid volumes (101–104 m3) are used to approximate the moment magnitudes of potential seismic events. The resulting moment magnitudes (−0.6 to 3.8) and short timescales of fluid infiltration (∼10 hr) are comparable to some slow‐slip events, such as tremors and low‐frequency earthquakes. This indicates that the voluminous fluid flow in a single fracture could be a key control on the generation of crustal fracturing and the induction of seismic activity above the tremor and slow slip events source regions in the lower–middle crust.

Keywords

• short‐lived fluid flow
• crustal fracturing
• voluminous fluid flow
• fluid‐rock reaction zone