New insights into the 2008-2009 Etna eruption from in-soil radon measurements and seismic activity

Abstract

One of the main aims of the WP5 Task 5.1 “Characterization of the threatening phenomena from space and ground” of the European MEDiterrranean Supersite Volcanoes (MED­SUV) project was the analysis of the Mt. Etna eruptive activity from a multidisciplinary perspective. In this paper, we take into account an eruptive event, which offers an intriguing case study to scrutinize the relationships between a few geochemical and geophysical parameters during a long-lasting (15 months) lava emission. The eruption started on 13 May 2008, three days after a lava fountaining, and finished on 6 July 2009. Based on continuous borehole measurements of in-soil radon (Rn) emission and ambient parameters (barometric pressure and air temperature measurements), we explore the variations of the gas before and during the eruptive activity in the light of local seismic activity, considering volcanic tremor and earthquakes. We can shed light on the dyke intrusion that fed this eruption also exploiting an exceptional point of view, as the station for the Rn flux measurements is located on a fumarole at an altitude of 2950 m above sea level and near (~1 km) the summit active craters. Accordingly, this study offers new insights on the recharging phases that preceded and accompanied the 2008-2009 eruption.