Almost all seismic events recorded since 2000 in the Campi Flegrei area have a tectonic origin, with depths less than 4 km, and no seismic evidence of significant magma migration has been found.
This is what emerges from the work carried out by an international team of scientists from the Department of Geophysics of the Doerr School of Sustainability at Stanford, the Vesuvius Observatory ofEngv and the Federico II University of Naples.
An active fault system, increasing seismic activity, and one of the most studied and feared volcanic areas in the world. Campi Flegrei, the beating heart of the western outskirts of Naples and Pozzuoli, are back at the center of scientific attention thanks to an international study that opens up new scenarios on the behavior of the caldera.
Published in the journal Science, the research is the result of a collaboration between Stanford University, the Vesuvius Observatory of the National Institute of Geophysics and Volcanology (INGV-OV), and the Federico II University of Naples. The title—"A clearer view of the current phase of unrest at Campi Flegrei Caldera"—is a clear statement of intent: to provide a clearer view of the current phase of "unrest," the state of instability that has kept the volcanic area under observation for years.
The eye of artificial intelligence
The study's true breakthrough lies in the use of artificial intelligence applied to seismograms collected by the INGV. Thanks to this technology, trained on seismic data recorded from 2000 to the present and enhanced by the increasingly widespread monitoring network, the researchers identified over 50.000 earthquakes between 2022 and mid-2025.
The result is a high-resolution seismic catalog that clearly identifies the distribution and nature of the events. Almost all are tectonic in origin, at depths less than 4 kilometers. A crucial fact: there is no evidence of significant magma migration toward the surface.
The ring fault system
AI also allowed scientists to precisely identify a ring fault system surrounding the caldera, extending from the mainland to the Gulf of Naples. This detail has never been observed with such clarity before.
"For the first time," explains Warner Marzocchi, professor at Federico II, "the seismicity detected on the mainland near Pozzuoli reveals specific, well-defined faults. This could lead to more accurate assessments of the seismic hazard and risk in the area."
The nature of the fluids involved also appears clearer: according to Anna Tramelli, a researcher at INGV, they are largely hydrothermal fluids, generated by the interaction between rock, gas, and water during fracturing processes.
A tool for the future
The analysis system, already operational, paves the way for near-real-time monitoring of the Phlegraean Fields. This prospect could radically transform the ability to detect changes in the caldera and, consequently, improve seismic and volcanic risk estimates.
"If it successfully passes the testing phase," the researchers emphasize, "it will be possible to detect even the smallest changes in the volcano's behavior, with a direct impact on the safety of the population."
Why it matters to understand
The importance of this work goes beyond the scientific data. Campi Flegrei They are one of the most densely populated volcanic areas in the world: approximately half a million people live directly in the affected area, millions more within a few kilometers.
Understanding whether an earthquake is linked to a simple fault settling or to a magma movement means reducing uncertainty and fears, providing a solid basis for civil protection decisions.
Studying the caldera with next-generation instruments, therefore, is not just an academic challenge but a vital necessity. Because here, more than anywhere else, the boundary between science and safety coincides with the daily life of an entire community.
CAMPI FLEGREI | Artificial Intelligence applied to develop a high-definition seismic catalog
An international team of scientists from the Department of Geophysics at Stanford's Doerr School of Sustainability, the Vesuvius Observatory of the National Institute of Geophysics and Volcanology (INGV-OV), and the University of Naples Federico II has just published the study, "A clearer view of the current phase of unrest at CAMPI FLEGREI Caldera," in the scientific journal Science. The work offers a clearer view of the current phase of seismic activity at CAMPI FLEGREI (unrest). The area of interest includes the densely populated areas of the western outskirts of Naples and the city of Pozzuoli, which in recent years has seen 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 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-level seismic catalogue
definition highlighted an active fault system and provided important
details on the origin of the phenomenon. In detail, the AI was trained using
the seismic catalogue compiled by INGV-OV since 2000 and has made use of the dense network
seismic strengthened over the years by the Authority also in response to the increase in
seismicity.
The results showed that almost all seismic events had
a tectonic origin, with depths less than 4 km and no evidence is found
seismic evidence of significant magma migration.
A ring fault system has been clearly identified, surrounding
the caldera uplift zone, extending both on land and
in the Gulf of Naples. “Within this ring structure the observed seismicity
highlights for the first time on the mainland near Pozzuoli specific faults
and well-defined that could lead to more precise estimates of seismic hazard and risk in this area,” says Professor Warner Marzocchi
of the University of Naples Federico II.
“These events come 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,
it's already up and running.
“This system, once it has passed the verification phase, could allow us to
identify even the smallest changes in near real time
seismic behavior of the Phlegraean Fields and, consequently, allow better
estimates of seismic and volcanic risk,” the researchers conclude.
The only seismicity that is not purely tectonic, composed of so-called events
“hybrids”, it was observed at depths less than a kilometer, near the dome
Accademia lava.
In short
Almost all seismic events recorded since 2000 in the Campi Flegrei area have a tectonic origin, with depths less than 4 km, and no seismic evidence has been found…
- This is what emerges from the work carried out by an international team of scientists from the Department of Geophysics at the Doerr School of…
- An active fault system, increasing seismic activity, and one of the most studied and feared volcanic areas in the world.
- The Phlegraean Fields, the beating heart of the western outskirts of Naples and Pozzuoli, are back at the center of scientific attention thanks to…
Key questions
What is the main point of the news?
Almost all seismic events recorded since 2000 in the Campi Flegrei area have a tectonic origin, with depths less than 4 km, and not…
Why is this news relevant?
This is what emerges from the work carried out by an international team of scientists from the Department of Geophysics at the Doerr School of…
Which detail helps us understand the case better?
An active fault system, increasing seismic activity, and one of the most studied and feared volcanic areas in the world.
The article discusses a very important topic for the safety of those living in the Phlegraean Fields, but the information is complex and not everyone can easily understand it. It would be helpful to have simpler and clearer explanations for the public.