A gas-slug model for basaltic Vulcanian eruptions at open-conduit volcanoes, constrained by textural characteristics and dynamics of the July 3rd, 2019, Stromboli eruption (Italy)
Main Article Content
Abstract
Stromboli is a unique open-conduit mafic volcano known for persistent Strombolian eruptions of highly porphyritic (HP) basalticshoshonite scoria. Stronger paroxysmal explosions occur once or twice per decade, ejecting low porphyritic (LP) golden pumice from deeper volatile-rich magma. The July 3rd, 2019, paroxysm showed features of a Vulcanian eruption—supersonic blast, ballistic ejection, and pyroclastic flows—despite Stromboli’s open-conduit basaltic nature. Textural analysis suggests that LP pyroclasts formed via rapid decompression, fragmentation, and quenching. This event likely resulted from shallow HP-filled conduit pressurization and failure triggered by a rising large gas slug. This caused top-down decompression, evacuating both HP and deeper LP magma. The proposed “basaltic Vulcanian” model better fits geophysical data than the traditional deep LP magma ascent model.
Downloads
Article Details
This work is licensed under a Creative Commons Attribution 4.0 International License.
© The Author(s).
Submission of an original manuscript to Volcanica will be taken to mean that it represents original work not previously published, and not being considered for publication elsewhere.
The Creative Commons Attribution 4.0 International License permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.
Accepted 2026-01-28
Published 2026-02-11