Compositional spatial zonation and 2005–2013 temporal evolution of the hydrothermal-magmatic fluids from the submarine fumarolic field at Panarea Island (Aeolian Archipelago, southern Italy)

摘要: Abstract The November 2002 submarine gas blast at Panarea Island (Sicily, southern Italy) was an unexpected reactivation event able to locally affect this hydrothermal-magmatic system whose the youngest eruptive products were dated 20,000 ± 2000 years BP. presence of magmatic gases (SO 2 and HF) in fumarolic discharges after violent exhalative indicative a input that temporary displaced hydrothermal system. A few months later these acidic indeed not detected any studied fumaroles. Nevertheless, new geochemical data obtained by periodical sampling up June 2013 suggest chemical–physical conditions completely restored with respect early nineties. Thus, burst has unequivocally caused permanent modification fluid circulation feeding In addition, strong compositional differences observed 46 collected 2012–2013 from fumaroles located different sites area, allowing distinguish three groups fumaroles: A) H - CO-rich gases, which also show relatively low Ar concentrations, B) S-rich having variable CO/CH 4 ratios, C) Ar-rich concentrations. Gases group are distributed along NW- NE-trending fault systems, whereas those B C discharge increasing distance intersection two indicating spatial control local tectonic setting. /CO ratios significantly lower than measured prior 2012. This would imply increase pressure depth, possibly continuous addition energy source reservoir. Continuation process may lead occurrence events next future, hypothesis is supported ongoing degassing activity surface notwithstanding decrease temperatures depth. geochemical, seismological ground deformation monitoring field highly recommended obtain precursory signals phenomena.