Geochemical continuous signals in seismic areas: the case of the Mugello Basin, Central Italy

The Mugello basin (Tuscany, Italy) is one of the areas with the highest seismic risk of Tuscany, having been subjected in the past to earthquakes up to Mw 6.38 (Rovida et al., 2020). As a part of a seismic prevention/prediction program of the Regional Government of Tuscany, the Mugello basin was chosen, ten years ago, as a monitoring site for possible hydrogeochemical precursors of seismic activity.For this purpose, the IGG-CNR of Pisa has realized an automatic continuous monitoring station, equipped with sensors for the concurrent measurement of temperature, pH, redox potential, electrical conductivity, CO2 and CH4 dissolved concentration (Cioni et al., 2007).With a stable temperature of 13°C and a permanent outflow of a few liters/minute (with reduced seasonal oscillations), the Postignana spring discharges low salinity waters (600 mg/l).