Almost 2000 years after the eruption that destroyed much of the Vesuvian territory and its cities, a team of researchers has developed a model that describes how the magma chamber that generated the eruption of 79 AD
Magmatic chamber that grew over the centuries preceding the event, to the point of significantly deforming the ground of a vast area extending beyond the volcanic edifice, as attested by numerous historical documents and geological data.
By integrating the physical and numerical model with geomorphological and archaeological evidence and with thermodynamic and petrological data, the researchers were able to develop a growth model of the magma chamber, confirming the archaeological data of uplift, from decimetric to metric, estimated from Naples city to Pompei and Herculaneum.
The study ''Magma reservoir growth and ground deformation preceding the 79 CE Plinian eruption of Vesuvius'', recently published in the prestigious journal 'Communications Earth & Environment' of the 'Nature' group, was conducted by the National Institute of Geophysics and Volcanology (INGV), in collaboration with the Department of Earth, Environmental and Resource Sciences of the University of Naples Federico II (DiSTAR-UniNA) and the Department of Biosciences and Territory of the University of Molise (DiBR-UniMOL).
The research was carried out within the research project 'Pianeta Dinamico' funded by the INGV.
“The integration of the deformation model with archaeological evidence of ground uplift and petrological data, including possible phases of growth of the magma chamber, has allowed us to reconstruct the sequence of thermomechanical processes that inevitably occur in the years preceding the Plinian eruptions,” explains Domenico Doronzo, volcanologist at the INGV – Vesuvius Observatory (INGV-OV) and co-author of the study.
“In particular,” continues Doronzo, “in the centuries preceding the eruption of 79 AD, the territory around Vesuvius underwent significant uplift accompanied by seismic events and degassing, all phenomena connected to the recharging of magma at depth.”
The volcanic activity of Vesuvius in the centuries preceding the eruption was characterized by a long phase of reactivation, laying the foundations for the preparatory phase of the eruption in the strict sense.
The research was then compared with other cases, both past and contemporary, of reactivation of volcanoes around the world, highlighting that, although the preparatory phases can last centuries, the transition to the irreversible eruptive phase could take much shorter times.
Another aspect highlighted by the study concerns "the different capacity of magma storage by magma chambers of different shapes, with the same observed ground deformation and volume of magma intruded into the chamber itself.
This means that in some chambers the irreversible phase is delayed, given the same initial conditions. A direct implication is that monitoring a single manifestation of volcanic activity, such as ground deformations alone, may not be sufficient to predict an imminent volcanic eruption” adds Elisa Trasatti, researcher at the National Earthquake Observatory of the INGV who participated in the research.
“It is essential that monitoring includes multi-parameter networks and that continuous integration is carried out between monitoring data (deformation, seismicity, degassing, gravity and temperature variations) and those deriving from research on active volcanoes, in particular on volcanoes that, on the basis of their geological and dynamic history, may repeat large-scale eruptions in the future, such as Plinian eruptions, in order to better understand the thermomechanical mechanisms that would lead to an eruption”, concludes Mauro Antonio Di Vito, Director of the Vesuvius Observatory and co-author of the study.
Article published on 30 June 2023 - 14:20
