Explosive eruptions at Stromboli volcano (Italy): a comprehensive geochemical view on magma sources and intensity range

Abstract A comprehensive understanding of the processes that occur during magmatic storage and pre-eruptive ascent—and their associated timescales—is critical to identifying potential precursory signals, developing robust volcano early-warning systems. Stromboli’s persistent activity comprises continuous degassing explosive ranges from hourly, low-intensity “normal” occasional, more violent, paroxysmal activity. While magma source drive normal are reasonably constrained, eruptive intermediate in magnitude intensity (i.e., major explosions) remains elusive terms classification, region, timescales. Here, we investigate 19 July 2020 explosion geophysical parameters place at upper limit explosions field, close small-scale paroxysms such as 2003 2007 events. The geochemical signatures matrix glass, olivine, melt inclusions, embayments—integrated with gas measurements—highlight important differences eruption source, ascent behaviour, timescales studied event when compared paroxysms. Melt inclusion volatile contents identify rise begins a slightly shallower (~9.5 km below sea level, b.s.l.) than for (11.4 b.s.l.), activation ponding zone 5–6 b.s.l.. This, combination glass compositions, suggests complex characterised by CO 2 buffering deep region self-mixing zone. Fe–Mg-diffusion modelling olivine indicates system perturbation starting ~20–25 days before onset, agreement timescale volcanic /SO ratio changes observed plume, significantly shorter prior (~4 months). dataset provides insights into controlling steady-state conditions broad spectra Stromboli bears implications forecasting.