Triggers mechanism and reservoir configuration preceding eruptions at Campi Flegrei
Charline Lormand1, Luca Caricchi1, Guido Giordano2, Roberto Isaia3
Affiliations: 1Department of Earth Sciences, University of Geneva, Rue des Maraîchers 13, 1205 Geneva, Switzerland (charline.lormand@unige.ch); 2Dipartimento Di Scienze, Università Degli Studi Roma Tre, L.Go S.L, Murialdo 1, 00146, Rome, Italy; 3Istituto Nazionale di Geofisica e Vulcanologia, sezione di Napoli Osservatorio Vesuviano, Via Diocleziano 328, 80124 Napoli, Italy
Presentation type: Poster
Presentation time: Friday 16:30 - 18:00, Room Poster Hall
Poster Board Number: 216
Programme No: 3.10.15
Abstract
The current unrest of Campi Flegrei caldera, Italy, which started in 2005 recently consisted of earthquake swarms and ground uplift of up to 20 mm/month. With 500,000 residents living in the red zone, it is essential to assess how the ongoing crisis will develop. Here, we use clinopyroxene-only thermobarometry based on supervised machine learning [1] on pyroclastic samples collected from the opening phase to the upper portion of the eruptive units from emblematic eruptions, varying in age, eruption style, and location within the caldera. Eruptions are all preceded by storage of magma at about 4 km depth and, in most cases, are also fed by hotter magma extracted from depths greater than 8 km. While some eruptions are likely triggered by the arrival of magma from depth, the trigger mechanism for other eruptions, especially the younger ones that occurred in the central sector (e.g., Santa Maria Delle Grazie, Solfatara), could be external to the magmatic system such as elastic crust weakening causing the arrival of magma from depth after the eruption begun. We find the shallowest recorded depths of magma emplacement to correspond to the current source of seismicity and deformation, and the greater depths to correspond to the deep reservoir highlighted by seismic and recent magnetotulleric surveys. This study provides insights on the preferred magma pathways potentially heralding a volcanic eruption, as well on the possible eruptive scenarios, which are crucial to consider for volcanic hazard management. [1] Ágreda-López et al. (2024) Computers & Geosciences, 193