Geochemical monitoring of the 2012 Po Valley seismic sequence: A review and update

A seismic swarm characterized by a Ml = 5.9 mainshock occurred in the Po Valley, northern Italy, in 2012. The area has been studied for active compressional tectonics since the beginning of the twentieth century. A variety of geophysical and geochemical parameters have been utilized with the purpose of identifying possible precursory signals. This paper considers groundwater level data and geochemical data both in groundwaters and in gases. All considered parameters have led to the conclusion that possible long and medium precursory trends have been identified in geofluids. No short-term precursors have been clearly identified. Hydrogeological and geochemical monitoring could be more effectively utilized in a different geological context, and seismic hazard reduction procedures could benefit from geofluid monitoring.