The history of Italy is irreversibly linked with volcanoes. Two thousand years ago, the eruption of Mount Vesuvius on the central coast of Italy annihilated the city of Pompeii, leaving victims' bodies frozen in ash. In fact, the word volcano is derived from Vulcan, the Roman god of fire. These connections are unsurprising, since the country sits atop a literal hotbed of volcanic activity.

Left: The Campi Flegrei volcanic network. Right: Mount Vesuvius, the volcano which destroyed Pompeii.

One large portion of this ancient volcanic network is known as Campi Flegrei, which roughly translates to “the burning fields”. The region consists of 24 individual craters, plus various geysers and vents, many of which are undersea. The largest concern of all is its location: Campi Flegrei is situated to the west of Naples, Italy, one of the top ten most densely-populated cities in Europe. Approximately 3.1 million people live in the Naples metropolitan area.

A photo from the International Space Station shows the features of Campi Flegrei. Source: NASA / Wikipedia

This Italian supervolcano has been laying relatively dormant for the last few centuries, but a scientific study published in Nature Communications journal last month indicates that it may be reawakening. In fact, the title of this study presents a worrying conclusion: “Magmas Near the Critical Degassing Pressure Drive Volcanic Unrest Towards a Critical State”. The study's abstract clarifies why this is happening:

Subscribe Today and Save!

Get the Mag

“At the [Critical Degassing Pressure] CDP, the abrupt and voluminous release of H₂O-rich magmatic gases can heat hydrothermal fluids and rocks, triggering an accelerating deformation that can ultimately culminate in rock failure and eruption. We propose that magma could be approaching the CDP at Campi Flegrei, a volcano in the metropolitan area of Naples, one of the most densely inhabited areas in the world, and where accelerating deformation and heating are currently being observed.”

Artist Michael Wutky painted this depiction of fumaroles in Campi Flegrei circa 1780.

The last documented eruption at Campi Flegrei was in 1538, and lasted 8 days, creating a new mountain. Volcanologists admit that the timing of any eruption is impossible to predict, but the data indicates that it's a distinct possibility in the near future. As a result, the Italian government has reportedly raised the supervolcano's threat level from green to yellow, and accelerated geothermal monitoring.

If you're curious about the potential dangers of volcanic activity closer to home, check out our “What If?” article on the Yellowstone supervolcano.

Written by Patrick McCarthy