Experts are worried about the supervolcano in Naples: “We don’t know what will happen next”

What are the Phlegraean Fields?

The “Campi Flegrei” are part of a supervolcano bubbling underground. The term comes from Greek and means ‘burning fields’. The gigantic crater extends over 150 square kilometers from the Mediterranean coast to the outskirts of Naples. 600,000 people live on this geological ticking time bomb. The “Campi Flegrei” are considered much more dangerous than the Vesuvius volcano.

What’s happening west of Naples?

In 2018, Zurich scientist Olivier Bachmann (50) and his team discovered that the Phlegraean Fields were at the beginning of a new caldera cycle. The magma chamber begins to fill. Gases and evaporating groundwater press against the rocks of the Earth’s surface and bend the entire coastal area upward. When the so-called fluids from the upper rock layers flow back into the magma chamber, the ceiling drops again.

“We had this so-called bradyseismos between 1982 and 1984. Then the activity calmed down again,” Olivier Bachmann told Blick. Now it is boiling again under the Phlegraean fields. “There is currently no volcanic activity, only high-temperature gas activity.” The swarm of earthquakes now indicates that the Earth’s surface is beginning to crack, Bachmann says. There are ground deformations in Pozzuoli Bay.

How dangerous is the new activity?

“At the moment there is no evidence that magma is rising,” says the professor of magmatic petrology at the Institute for Geochemistry and Petrology of ETH Zurich. But of course it is possible. “We need to keep a close eye on magma movement in the coming weeks. The magma is still about six to eight kilometers deep. “As the magma moves, the earthquakes become stronger.”

Is there a threat of a super eruption?

“We cannot say exactly at the moment. There is currently earthquake activity and deformation of the ground, but such turbulent periods have occurred in the past (e.g. in the 1980s) without necessarily leading to an eruption,” answers Olivier Bachmann, “we don’t know what will happen next to happen”. Supervolcanoes are very difficult to assess. “It could be another thousand years until the next eruption. But it can also happen very quickly. We may not be able to predict an eruption until a few days before the eruption, if at all,” says Bachmann.

What are the possible scenarios?

“The system could settle down again without an impact on the surface and therefore an eruption,” says Olivier Bachmann. A second scenario would be a small phreatic eruption without magma involvement. Then water vapor would escape. A smaller eruption, such as that of October 1538, would also be possible, according to the scientist. At that time there was a major earthquake and lava flows that formed a 133 meter high cinder cone, Monte Nuovo. There was heavy ash fall in Naples. The worst-case scenario, however, would be a super eruption like the one that occurred 39,000 years ago. At that time, pyroclastic flows with a temperature of 500 degrees flowed at high speed over an area of ​​30,000 square kilometers. Half of Europe and the Mediterranean were covered in an inch-thick layer of ash.

And what if a super eruption does occur?

“That would be a nightmare,” says Olivier Bachmann. Four million people would have to be evacuated immediately. “The region around Naples would be largely destroyed. A large amount of volcanic particles in the atmosphere would disrupt air traffic and global climate and lead to unpredictable consequences around the world,” the expert continued. A so-called volcanic winter would occur. For example, depending on the wind direction, Switzerland would be covered in dust and ash after just a few hours, the sky would darken and the temperature would drop. Bachmann: “But such supereruptions are extremely rare and highly unlikely.”