Re-pressurized magma at Mt. Etna, Italy, may feed eruptions for years

Abstract

Identifying and monitoring the presence of pressurized magma beneath volcanoes allows for improved understanding of internal dynamics and prediction of eruptions. Here we show with time-repeated tomography clear evidence that fresh melts accumulate since 2019 in three reservoirs located at different depths in the central feeding system. In these three volumes, we observe a significant reduction of seismic wave velocity, an anomaly that has endured for almost two years. Reservoir re-pressurization induced seismicity clusters around the pressurized volumes within high fluid pressure compartments. This indicated a sharp change in volcano behavior, with re-pressurization of the central system replacing two-decade-long, flank collapse-dominated dynamics. The volume where the velocities are altered is remarkable in size, suggesting the injection of new melt, and that erupted lava represents only a small percentage. Our findings suggest that ongoing volcanic recrudescence can persist.