Plumbing system dynamics during the 2024 paroxysmal sequence at the Voragine crater of Mt. Etna volcano as revealed by the olivine crystal cargo

Abstract

The sequence of six paroxysmal eruptions that occurred between July and August 2024 at Mt. Etna’s Voragine crater has been investigated in order to constrain the plumbing system dynamics. Whole-rock and glass major-element analyses have been integrated with a detailed petrological study of erupted products, focusing on olivine major-element compositions to track magma storage and transfer dynamics leading to the eruptions. Olivine chemistry and thermodynamic modeling indicate an intermediate reservoir at ∼2.7 km b.s.l. as the main magma storage region. Fe–Mg diffusion chronometry on zoned olivines constrains magma transfer timescales, suggesting mafic recharge from depths of 6–8 km b.s.l. over 3—4 months, followed by progressive replacement of magmas occupying the shallower levels 1—3 weeks before the onset of Strombolian activity in mid-June. Compared to the last lava fountain activity at Voragine in 2015–2016 and the long-lasting sequence at South East Crater in 2020—2022, the 2024 magmas underwent slower transfer from depth and longer residence at intermediate storage levels, suggesting important modifications in the working modes of the current plumbing system.