A new study reveals previously unseen details about the Caldera's seismic activity.
An international team of scientists from the Department of Geophysics of the Doerr School of Sustainability at Stanford, the Vesuvius Observatory of the National Institute of Geophysics and Volcanology (INGV-OV) and the University of Naples Federico II has just published, in the scientific journal Science, study A clearer view of the current phase of unrest at Campi Flegrei Caldera.
The work offers a clearer vision of the seismic activity phase currently underway in the Campi Flegrei (unrest). The area of interest includes the densely populated areas of the western outskirts of Naples and the city of Pozzuoli, where in recent years there has been a marked increase in seismic activity, gas emissions, and ground uplift.
The researchers used artificial intelligence (AI) techniques developed at Stanford University and applied to the seismograms recorded by the INGV in the Campi Flegrei area, identifying over 50.000 earthquakes in the period between 2022 and mid-2025. The high-definition seismic catalogue highlighted a system of active faults and provided important details on the origin of the phenomenonIn detail, the AI was trained using the seismic catalog compiled by INGV-OV since 2000 and made use of the dense seismic network strengthened over the years by the institution also in response to increased seismicity.
The results showed that almost all seismic events have a tectonic origin, with depths less than 4 km and there is no seismic evidence of a significant magma migration.
It was clearly a ring fault system has been identified, surrounding the caldera uplift zone, extending both on land and into the Gulf of Naples. "Within this ring structure, the observed seismicity highlights for the first time on the mainland near Pozzuoli specific and well-defined faults, which could lead to more precise estimates of the seismic hazard and risk in this area.", says Professor Warner Marzocchi of the University of Naples Federico II.
The only seismicity that is not purely tectonic, composed of so-called "hybrid" events, has been observed at depths of less than one kilometer, near the lava dome of Accademia.
"These events arise from the interaction between rock, fluids and gases during a fracture.. Further analysis suggests that the fluids involved would be of hydrothermal type", declared INGV researcher Anna Tramelli.
The new seismic signal analysis system, implemented during the research, is already in operation.
"This system, once it has passed the verification phase, could allow us to identify in near real time even the smallest changes in the seismic behavior of the Phlegraean Fields and, consequently, allow for better estimates of seismic and volcanic risk." conclude the researchers.
Useful links
National Institute of Geophysics and Volcanology (INGV)
University of Naples Federico II
Stanford's Doerr School of Sustainability
Photo - Image of the Phlegraean Fields acquired by drone. Credit: Alessandro Fedele, INGV researcher.
Image - Earthquake locations contained in the new high-definition seismic catalog.
The different shades of red indicate different earthquake depths.