GNGTS 2024 - Atti del 42° Convegno Nazionale

Session 1.2 GNGTS 2024 The magma chamber before the 79 CE Plinian erupton of Vesuvius D.M. Doronzo 1 , E. Trasat 1 , I. Arienzo 1 , H. Balcone-Boissard 2 , D. Barra 3 , G. Aiello 3 , V. Amato 4 , M.A. Di Vito 1 1 Isttuto Nazionale di Geofsica e Vulcanologia, Italy; 2 CNRS-Sorbonne Université, France; 3 Università degli Studi di Napoli Federico II, Italy; 4 Università degli Studi del Molise, Italy The 79 CE erupton of Vesuvius is the frst documented Plinian erupton, also famous for the archaeological ruins of Pompeii and Herculaneum. Although much is known regarding the erupton dynamics and magma reservoir, litle is known about the reservoir shape and growth, and related ground deformaton. Numerical modelling by Finite Element Method was carried out, aimed at simulatng the reservoir growth and ground deformaton with respect to the reservoir shape (prolate, spherical, oblate) and magma overpressure. The modelling was tuned with volcanological, petrological and paleoenvironmental ground deformaton constraints. Results indicate that the highest magma overpressure is achieved considering a prolate reservoir, making it as the most likely shape that led to erupton. Similar deformatons but lower overpressures are obtained considering spherical and oblate reservoirs. These results demonstrate that ground deformaton may not be indicatve of erupton probability, style/size, and this has direct implicatons on surveillance at actve explosive volcanoes. References Doronzo, D.M. et al. Magma reservoir growth and ground deformaton preceding the 79 CE Plinian erupton of Vesuvius. Commun Earth Environ 4, 211 (2023). htps://doi.org/10.1038/ s43247-023-00880-9. Corresponding author: domenico.doronzo@ingv.it