In a new multidisciplinary study, the phases that preceded, over the years, the iconic eruption of Pompeii in 79 AD have been reconstructed, opening up new research fronts on theprediction of major eruptions
Almost 2000 years after the eruption which destroyed much of the Vesuvius territory and its cities, a team of researchers has developed a model describing how the magma chamber that generated the 79 AD eruption grew over the centuries that preceded the event, to the point of clearly deforming the soil of a vast area that extends beyond the volcanic edifice, as evidenced by numerous historical documents and geological data.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 model of growth of the magma chamber, confirming the archaeological data of uplift, from decimetric to metric, estimated by the city of Naples in Pompeii and Herculaneum.
I study '''', recently published in the prestigious journal 'Communications Earth & Environment' of the 'Nature' group, was conducted by theNational Institute of Geophysics and Volcanology (INGV), In collaboration with the and . The research was carried out as part of the 'Dynamic Planet' research project funded by INGV.
"The integration of the deformation model with archaeological evidence of soil uplift and petrological data, including the possible accretion phases of the magma chamber, has allowed us to reconstruct the sequence of thermo-mechanical processes that inevitably occur in the years preceding the Plinian eruptions ”, explains Domenico Doronzo, volcanologist at INGV - Osservatorio Vesuviano (INGV-OV) and co-author of the study. "In particular", continues Doronzo, ''in the centuries preceding the eruption of 79 AD, the area around Vesuvius underwent significant uplift also accompanied by seismic events and degassing, all phenomena connected to the deep recharge of magma''.
The activity volcano 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 magma storage capacity of magma chambers of different shapes, with the same observed soil deformation and volume of magma intruded into the chamber itself. This means that in some chambers the irreversible phase is delayed, with 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.” he adds Elisa Trasatti, researcher at the INGV National Earthquake Observatory (INGV-ONT) 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, outgassing, gravity and temperature variations) and those deriving from research on active volcanoes, in particular on volcanoes which, based on geological and dynamic history, could repeat large-scale eruptions in the future, such as Plinian eruptions, in order to better understand the thermo-mechanical mechanisms that would lead to an eruption”, concludes Mauro Antonio Di Vito, Director of the Vesuvius Observatory (INGV–OV) and co-author of the study.
Link to the study:
Quote: Doronzo, DM, Trasatti, E., Arienzo, I. et al. Magma reservoir growth and ground deformation preceding the 79 CE Plinian eruption of Vesuvius. Commun. Earth Environ. 4, 211 (2023).
Figure 1. Map of ground uplift in the Vesuvius area prior to the eruption.
The arrows indicate: black = archaeological site; red = prolate chamber model; blue = spherical chamber model; green = oblate chamber model.
The concentric circles represent lift in metres.
Figure 2. Scheme of the three models used for the simulation of the deformations.
The different shapes are: left = prolate chamber; center = spherical chamber; right = oblate chamber.
The color scale represents the extent to which the edges of the magma chamber have moved in meters. The three sections are centered at Somma-Vesuvius.