Geochemical evidence of the renewal of volcanic activity: the 2007 Stromboli (Italy) eruption

Abstract

Geochemical surveillance has been carried out at Stromboli since 1999 using discrete and continuous monitoring of thermal waters and soil degassing. On 27 February 2007 a new eruption began which lasted until 2 April; it was characterized by effusive activity on the Sciara del Fuoco and also by a paroxistic event (15 March). This crisis represented an opportunity to refine the model developed previously and to improve our understanding of the relationship between the magmatic dynamics of the volcano and geochemical variations. The main aim of this research was to evaluate the level of criticality of the volcanic activity. The SO2 fluxes of the degassing plume and the CO2 fluxes emitted from the soil at Pizzo Sopra la Fossa are herein presented. Furthermore, we propose a refined geochemical model of fluids circulation, including plume and summit fumarolic soil degassing. Noteworthy geochemical signals of volcanic unrest were also clearly identified (before, during and after the effusive activity) in the degassing plume as well as in the degassing from the soil at the summit.