According to a preprint study posted on arXiv, researchers have identified a self-reinforcing pattern of seismic and ground activity that could culminate in a dramatic change to the volcano’s behavior.
Rising Activity Signals Accelerating ChangeOver the past 75 years, Campi Flegrei has exhibited intermittent unrest, with periods of ground uplift and earthquakes recorded in the 1950s, 1970s, and 1980s.
These episodes progressively weakened the caldera’s crust, leaving it more susceptible to future stress.
Campi FlegreiCredit: CanvaHistorical Unrest Shapes Future RiskPast periods of volcanic unrest are critical to understanding Campi Flegrei’s current state.
Each seismic or uplift event stretches the caldera’s crust slightly further, incrementally reducing its ability to accommodate future stress.
A new analysis of Campi Flegrei, the volcanic caldera near Naples, Italy, indicates the system is accelerating toward a potential geological shift within the next decade. According to a preprint study posted on arXiv, researchers have identified a self-reinforcing pattern of seismic and ground activity that could culminate in a dramatic change to the volcano’s behavior. While the exact outcome remains uncertain, the implications for the half-million residents in the surrounding area are significant.
Rising Activity Signals Accelerating Change
Over the past 75 years, Campi Flegrei has exhibited intermittent unrest, with periods of ground uplift and earthquakes recorded in the 1950s, 1970s, and 1980s. These episodes progressively weakened the caldera’s crust, leaving it more susceptible to future stress. Since 2005, the volcano has shown consistent signs of accelerating activity, including roughly 4.6 feet (1.4 meters) of uplift in the caldera floor, likely driven by the movement of volcanic gases and magmatic fluids beneath the surface.
“Our paper identifies when the system is likely to reach a breaking point, but it cannot determine what will happen at that breaking point with the current data,” said Davide Zaccagnino, a postdoctoral researcher at the Southern University of Science and Technology in Guangdong, China. The research highlights that the increase in activity is not linear but self-feeding, meaning the acceleration itself is accelerating, a phenomenon referred to as finite-time singularity.
Campi Flegrei
Credit: Canva
Historical Unrest Shapes Future Risk
Past periods of volcanic unrest are critical to understanding Campi Flegrei’s current state. Each seismic or uplift event stretches the caldera’s crust slightly further, incrementally reducing its ability to accommodate future stress. “At each emergency, the crust is being stretched just that bit further, so the later emergencies are building on the previous ones,” explained Christopher Kilburn, volcanologist at University College London to LiveScience. This compounding effect suggests that the caldera may be approaching a structural threshold where even minor stress could trigger a significant geological event.
The caldera’s history underscores the potential danger. It formed approximately 40,000 years ago in a massive eruption, and smaller explosive events, including the formation of Monte Nuovo in 1528, demonstrate that even moderate activity can dramatically reshape the landscape. The present acceleration in seismicity and ground uplift could precede an eruption, though the study notes that other forms of structural transition are also possible.
Aerial view of Solfatara in Pozzuoli, near Naples, Italy. It is a shallow volcanic crater that is part of the Phlegraean Fields volcanic area. It is a dormant volcano. In the background, the Mediterranean Sea. Credit: Shutterstock
Modeling The Volcano’s Future
Zaccagnino and his colleagues applied physics-based models to categorize the type of acceleration observed at Campi Flegrei. Exponential acceleration, in which activity increases at a fixed rate, contrasts with the observed finite-time singularity, where the speed of acceleration itself is growing. This distinction is crucial for predicting whether the volcano’s crust will fail and what form that failure might take.
The study’s modeling suggests that the current self-reinforcing pattern could persist until around 2030–2034. Beyond this point, the caldera is expected to reach a critical stage where the accumulated stress must be released. The exact nature of this transition, whether a large eruption, smaller explosive events, or other geological shifts, is still unknown. The research team is developing a continuous forecasting system that updates predictions based on the latest seismic and ground movement data, providing valuable tools for emergency management agencies.
Uncertainty Remains Despite Clear Patterns
Despite the acceleration patterns, researchers caution against interpreting this as a specific eruption forecast. “Things are changing,” Kilburn said, “and, therefore, past experience is not necessarily a good guide to the future.” The study, available on arXiv, emphasizes that while the caldera’s behavior is increasingly active, multiple outcomes remain possible. Understanding these dynamics is key to preparing for potential emergencies, especially given the dense population around Naples.
The findings highlight the need for ongoing monitoring and improved predictive models. By tracking self-reinforcing acceleration in volcanic activity, scientists hope to anticipate critical transitions before they occur, allowing for better planning and mitigation in one of Europe’s most geologically complex regions.
