Hundreds of small tremors have struck the densely-populated volcanic region of Campi Flegrei (Phlegraean Fields) near Naples in recent weeks, leading Italian authorities to reevaluate evacuation strategies.
The latest event, a magnitude 4.0 earthquake, occurred on Monday, and prompted experts to issue warnings of potential intensification in the near future.
Last week, the region experienced a 4.2-magnitude earthquake, the most powerful in 40 years, according to the National Institute of Geophysics and Volcanology (INGV). Although the tremors are causing concern, experts at INGV emphasize that they do not necessarily indicate an imminent volcanic eruption.
In a study published earlier this year, INGV scientists raised the possibility that the caldera's movements could rupture its crust, but that there are no certain reasons to anticipate a massive volcanic eruption.
"The seismic activity has been intensifying for months. We have observed over 3,000 tremors since the start of 2023," Gianfilippo De Astis, senior researcher at INGV, told media Tuesday. "Only 65, however, were above a 2.0 magnitude."
These phenomena, known as "bradyseism," have been ongoing in the Campi Flegrei area for thousands of years and involve a cyclical process of ground level rising and falling.
While the recent tremors have not caused damage or injuries, they have raised concerns about the logistics and impact of evacuating thousands of people, effectively putting pressure on local authorities and the government. Experts have advised Naples city council to conduct safety checks on critical infrastructure such as hospitals, schools and public buildings.
Civil protection minister Nello Musumeci announced the acceleration of drafting "exodus plans in the event of an emergency," which will be discussed at the next cabinet meeting. Current evacuation plans call for the relocation of hundreds of thousands of people from the most dangerous areas to other Italian regions.
A 2022 study by the National Research Council (CNR) estimated that an immediate evacuation of the entire Campi Flegrei area could cost around 30 billion euros annually, with a negative impact on Italy's GDP of approximately 1%. The risk of a volcanic eruption in the entire Southern Campania region, which includes Naples, would affect about three million people located within 15 to 20 kilometers of a potential eruption.
Updating the evacuation plans is essential, but it presents a complex challenge, according to De Astis. Enlarging escape routes to facilitate a quicker exodus is crucial, but dealing with psychological factors, such as residents refusing to leave their homes, poses an unpredictable challenge in any emergency scenario.