In Italy, a giant volcano draws attention to itself with many small earthquakes, among other things. Experts fear the possibility of an imminent volcanic eruption.
LONDON / NAPLES – Etna, Vesuvius, Stromboli – Italy has many volcanoes that attract attention with activity from time to time. One of these volcanoes is particularly sensitive: Mount Vesuvius in southern Italy is one of the most dangerous volcanoes on Earth. But very close by is another particularly dangerous area, classified as a “supervolcano”: the Phlegraean Fields (Campi Flegrei).
It is an area that extends over 150 square kilometers and begins right on the outskirts of Naples. The Italian islands also include Ischia, Procida, and Nicida. In the Phlegraean Fields region there are countless thermal springs, the ground can get very hot due to volcanic activity, and there are more than 50 eruption hotspots. Two-thirds of the volcano’s caldera, a bowl-shaped structure formed by eruptions, is submerged in water. About 360 thousand people live on the giant volcano. Phlegraean fields and Vesuvius volcano share a common magma chamber at a depth of about ten kilometers.
The last Italian Phlegrean volcano erupted in 1538
The last eruption of the supervolcano Phlegraean Fields dates back to 1538, but the volcano has been very turbulent for the past 70 years. According to experts, tens of thousands of small earthquakes were measured during this period, which sent the coastal city of Pozzuoli nearly four meters high.
In a new study, researchers from University College London and the Italian National Research Institute of Geophysics and Volcanology (INGV) closely examined the supervolcano. The study was in the journal nature Earth and Environment Communications published And it shows: Phlegrean fields have become weaker and more likely to rupture, making volcanic eruption more likely.
A research group is investigating the supervolcano Campi Flegrei in Italy
To come to this conclusion, lead author Christopher Kilburn’s research team applied a volcanic fracture model to a supervolcano. The model helps explain earthquake patterns and ground elevation. Research group conclusion: Parts of the volcano have extended almost to the point of breaking. Co-author Nicola Allesandro Pino explains in a communication: “Our results show that parts of the volcano are weakening. This means that it can crack, even if the tensions tearing it apart are lower than during the last crisis 40 years ago.”
“Our new study confirms that Campi Flegrei is close to erupting,” adds lead author Kilburn. However, he also qualifies: “This does not mean that a volcanic eruption is guaranteed. A rupture can cause a crustal rupture, but magma still needs to be pushed into the right place for an eruption to occur.”
The supervolcano in Italy is behaving as expected
Kilburn’s research group first applied their model to the supervolcano in 2017 and found that Campi Flegrei has been behaving as expected since then: There have been an increasing number of small earthquakes – in April alone, more than 600 small tremors were recorded, as many. Like never before in a month. In addition, the ground under the city was raised by about ten centimeters every year.
According to the statement accompanying the study, this activity is related to the movement of fluids at a depth of about three kilometers below the surface. The last turbulent phase of the supervolcano was likely caused by molten gas entering cracks in the rock and filling the three-kilometer-thick crust like a sponge. Earthquakes occur when faults are displaced due to crustal expansion. The pattern of 2020’s earthquakes suggests that rocks don’t respond elastically: they crack, rather than bend. “We can’t see what’s going on underground,” reminds co-author Stefania Danesi. “Instead, we need to decipher the clues that the volcano is giving us, which are earthquakes and Earth-lifting.”
We can’t yet say for sure what will happen. It is important to be prepared for all developments.
The eruption of the giant Italian volcano is not inevitable
In the study, the research team explains that the disturbances have been cumulative since the 1950s, which means that a final eruption may be preceded by relatively weak signals — such as less ground elevation and fewer earthquakes. But the eruption of a supervolcano is not inevitable, the research group stresses. “It’s like any volcano that’s been dormant for generations,” explains co-author Stefano Carlino. “Campi Flegrei could move into a new routine of gently ebbing and flowing as seen on similar volcanoes around the world, or simply rest. We cannot yet say for sure what will happen. It is important that we be prepared for all developments.”
In the next step, the research team wants to apply their volcano model to other volcanoes that have awakened after a long period of dormancy. The goal is to find more reliable criteria for whether a volcanic eruption is likely to occur. Currently, eruptions are predicted using the statistical data of each individual volcano, rather than applying basic principles to multiple volcanoes. This study is the first of its kind to predict volcanic eruptions at an active volcano. “It is an important step towards our goal of improving eruption prediction around the world,” said lead author Kilburn. (unpaid bill)