Hazard from ballistics during the 2020-22 paroxysmal eruptions at Mount Etna

In recent decades, Etna produced several sequences of energetic lava fountains from the summit craters, feeding several-km high eruptive columns, as well as lava flows. The last sequence, which started on December 2020 and ended on February 2022, produced sixty-two lava fountains episodes from the South-East Crater. The major issue associated with this type of events is the fallout of ballistic particles around the summit craters, sometimes reaching some of the most touristy areas of the volcano. The rather frequent activity has posed primary questions on how the impact associated with the fallout of these particles can be estimated. We present in this work field data collected after the lava fountain of February 21, 2022, during which several large ballistics fell just southeast of the summit craters, in the area of the Barbagallo Craters (∼2900 m a.s.l.). Hence, we collected samples and performed laboratory analyses in order to retrieve their size, shape and density. Values obtained, together with the quantitative analysis of lava fountain, have been compared with results acquired through “Eject!”, a calculator of ballistic trajectories during explosive eruptions. We therefore compared the main eruptive conditions occurred during the lava fountain of February 21, 2022 with other data obtained by other remote sensors. This work is a first step to identify a real-time and free available system capable of assessing the possible impact by fallout during the Mt. Etna lava fountains, in order to mitigate the risk associated to fallout of large ballistics.