Quantifying Strombolian Activity at Etna Volcano

Understanding the dynamics of mild explosive activity is a fundamental tool for hazard assessment at open conduit volcanoes. This particularly critical task Etna volcano. in fact characterized by frequent, activity, punctuated lava flows and paroxysmal events (‘lava fountains’), which, because their greater impact, have been main target studies, whereas more frequent Strombolian has overlooked. As result, impact associated hazards never quantified, despite extensive monitoring surveillance activities carried out on this In paper, we analyze video recordings sequence explosions occurring summit craters Mt. Etna, Italy, February 2020. Data were also integrated with petrographic analysis collected samples, drone surveys performed same time as recordings. We estimate frequency (20–12 per min); particle exit speeds (1–50 m/s), erupted mass (100–102 kg) those explosions. A very regular, small-scale (marked single burst gas breaking magma free surface into bombs lapilli fragments) was occasionally larger explosions, (at least one every 5 min), longer duration, fed volumes, consisting two to three distinct pulses followed stationary phase. found that repose times between follows log logistic distribution, which agreement behavior vent activity. The four largest analyzed detail: they emitted particles median diameters (Mdphi) ranging from ?10.1 ?8.8 phi, bimodal distributions.