Rome – The intensifying earthquakes that have been shaking the Campi Flegrei for months, with tremors exceeding magnitude 4 and causing localized damage and significant apprehension between Pozzuoli and Bagnoli, now have a more precise scientific explanation.
It is no longer (or not only) a simple elastic "stretching" of the Earth's crust due to the uplift of the ground (bradyseism), but the birth or reactivation of a real fault.
This is what emerges from a new, important study published today in the prestigious journal Communications Earth & Environment (Nature group), the result of a collaboration between the University of Roma Tre and the National Institute of Geophysics and Volcanology (INGV).
From widespread earthquake to fracture
The Phlegraean Fields have always been under observation. Since 2005, the caldera has resumed its activity, with ground uplift, seismic activity, and increased fumarolic emissions. But since 2023, the situation has clearly accelerated. Earthquakes have become stronger and more frequent, concentrated in a specific area.
The study, titled "Birth and Growth of a Volcanotectonic Fault During the Current Volcanic Unrest at Campi Flegrei Caldera (Italy), analyzed the enormous amount of data collected. The researchers documented a crucial transition: until 2023, the area was characterized by widespread microseismicity; today, the energy is concentrating along a well-defined plane.
In simpler terms: if previously the crust "bent" under the pressure (elastic response), now it has passed its breaking point and has begun to "split", creating or reactivating a fault.
The implications of the study
This discovery is not just an academic refinement, but has direct implications for understanding the phenomenon and managing risk.
It might interest you
"The observed phenomenon is fundamental to explaining the location and focal mechanisms of earthquakes," emphasizes Guido Giordano, full professor at Roma Tre University and coordinator of the research. The fact that the crust is breaking "suggests that the crust's behavior has changed over time."
This, Giordano explains, is important not only for "strengthening monitoring" but also for "defining the maximum expected magnitude." Understanding the geometry and nature of this fault is essential for estimating the maximum power of future earthquakes in the area.
The power of data
The research follows a line of studies that had already noted a change in the relationship between uplift and the number of earthquakes, but now offers a clear physical explanation: fracturing.
"Our investigation benefited from a huge amount of high-quality experimental data, analyzed with innovative methodologies," adds Francesca Bianco, Research Director at the INGV. "In this case too, the combination of monitoring and scientific research proved essential for gaining new insights into the processes underway at Campi Flegrei."
According to Dr. Bianco, this new interpretative model provides "possible keys to understanding even small-scale anomalies," such as those recently recorded in the Monte Olibano area.
Professor Francesco Salvini and Dr. Giada Alfonsi also participated in the research for Roma Tre, and Dr. Anna Tramelli, Dr. Mauro Di Vito, and Dr. Claudio Chiarabba for the INGV.
(The photo shows the geographic distribution of earthquake epicenters detected by the INGV-Osservatorio Vesuviano seismic network between 2018 and 2024. Each image also shows the depth location of the earthquake hypocenters, viewed along the north-south and east-west directions.)
Comments (1)
The article explains the latest developments regarding the earthquakes in Campi Flegrei well. But I wonder if precautionary measures have already been implemented to protect the population living in the areas near Pozzuoli and Bagnoli.