A supervolcano is waking up from a centuries-long sleep, scientists fear, and it could be ‘devastating’ if it erupts.
Campi Flegrei, or ‘burning fields’ in Italian, is a vast volcanic region that includes nearby Mount Vesuvius.
The eight-mile-wide area has been mostly eruption-free since 1538, when Naples saw a week of lava and smoke that formed Mount Nuovo.
But the blast was nothing compared to the eruption 40,000 years ago, so strong that the ash clouds and gas changed the Earth’s climate.
Experts have long believed Campi Flegrei could erupt again, with the volcanic alert level being yellow since 2012.
But a burst of activity – hundreds of small, shallow earthquakes as recently as Sunday and the earth swelling and sinking – is raising fears it might come sooner than later.
Will Campi Flegrei erupt?
A 4.4 magnitude quake hit Pozzuoli and Bagnoli in March, the strongest in 40 years. While 6,000 tremors have occurred in the last six months.
A new study by Italy’s National Institute of Geophysics and Volcanology says the Solfatara crater is also spewing up to 5,000 tons of gas a day.
The institute said that 80% of the carbon dioxide is coming from magma, while the rest is from hot liquids and calcite rocks interacting, another possible sign of the volcano’s awakening.
One reason for the rise in seismic activity is that layers of the large, caldron-like crater that Campi Flegrei is in are weakening.
Layers about 4km deep in the crater, called a caldera, have been softening since 2005 and the crust is now starting to crack.
The team said there are two possible outcomes based on their findings. The magma will keep swirling beneath the surface before cooling, causing a ‘failed eruption’, or a ‘large volume’ of magma about 8km deep could ‘eventually’ break out.
What would happen if the supervolcano erupts?
Campi Flegrei, only 1,000 miles from London, stretches out into the sea, meaning that an eruption could cause tsunamis, while plumes of ash could blot out the sun, lower temperatures and impact food supplies.
Around 360,000 people live in the area, also called the Phlegraean Fields, and it is less than seven miles from Naples, home to 1million people.
But Bill McGuire, a professor emeritus in geophysical and climate hazards at University College London, doubts that Campi Flegrei erupting would be world-ending – if it even happens.
Speaking to Metro, he said: ‘In terms of what an eruption would look like, it would all depend on the scale. A small eruption, like 1538, would probably result in local lava flows and ashfall across the Naples area. Damaging, disruptive and costly, but not devastating.
‘A blast on the scale of the one that happened around 40,000 years ago would cause regional devastation and would reduce global temperatures for a number of years, bringing big problems in terms of growing crops.’
The authorities have evacuation plans for the millions living in the wider Naples area, with officials posting tremor updates every six hours.
McGuire added: ‘We will just need to keep monitoring activity and wait and see.’
Matthew Watson, a professor of volcanoes and climate at the University of Bristol, said that Campi Flegrei erupting would be ‘grave’.
He told Metro: ‘This is due to both a large population living nearby and the scale at which an eruption might happen.
‘Whilst the consequences of a large eruption there would be grave indeed and felt across the world, it is important to remember that eruptions of that size are very, very rare.
‘It is important to prepare and plan for such events, as best we can, but talk of an imminent supervolcanic eruption is unfounded.’
Christopher Kilburn, a professor of volcanology and geophysical hazards at UCL, said that the National Institute of Geophysics and Volcanology’ findings aren’t too surprising.
He said to Metro: ‘Campi Flegrei is a volcano, after all. The new studies, though, are helping to build a clearer picture of what is happening underground and whether another eruption is likely after nearly 500 years.’
Kilburn, who has studied Campi Flegrei with Italian colleagues for more than 25 years, said talks of a super-eruption are ‘misleading’.
He said: ‘The dozens of eruptions from the volcano in the past 15,000 years have been thousands of times smaller than that.
‘These smaller sizes are the most likely should another eruption occur – certainly a menace to the 500,000 people living in Campi Flegrei, but not one that “could plunge the planet into chaos” as some headlines suggest.’
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