Seismic fluid correlation revealed by the change of friction coefficient in the Northeastern Noto Peninsula

In this study, by analyzing the dynamic changes in the friction coefficient, the evolution patterns of fluids at different times and depths and their effects on earthquake occurrence in the northeastern Noto Peninsula are elucidated. The results show that the existence of fluids reduces the friction coefficient of faults and affects seismicity, especially during the 2023 M_W6.5 earthquake and 2024 M_W7.5 earthquake. In addition, on the basis of seismic data and geochemical evidence, fluid may have originated in the mantle through ancient magma channels. The fluid infiltrates into the upper crust and accumulates in the fault system. The accumulated fluid led to the occurrence of the M_W7.5 earthquake. After that, the fluid gradually migrated to 0–6 km along the fault and drained through the fault to the surface. A significant increase in the shallow (0–27 km) friction coefficient after the earthquake indicates that the role of the fluid gradually weakened.