Naples astride a rumbling mega-volcano

PARIS: A slumbering Campi Flegrei volcano under the Italian city of Naples shows signs of ‘reawakening’ and may be nearing a critical pressure point, according to a study published Tuesday.

Italian and French scientists have for the fi rst time identified a threshold beyond which rising magma under the Earth’s surface could trigger the release of fluids and gases at a 10- fold increased rate.

This would cause the injection of high-temperature steam into surrounding rocks, said lead author Giovanni Chiodini, a researcher at Italy’s National Institute of Geophysics and Volcanology in Bologna.

“Hydrothermal rocks, if heated, can ultimately lose their mechanical resistance, causing an acceleration towards critical conditions,” he told AFP by email. It is not possible at this time to say when — or if — the volcano will erupt anew, he said.

If it did, however, ‘ it would be very dangerous’ for the halfmillion people living inside and near the caldera, he added, using the scientific name for the bowllike depression created after a volcano blows its top.

Since 2005, Campi Flegrei has been undergoing what scientists call ‘ uplift’, causing Italian authorities to raise the alert level in 2012 from green to yellow, signalling the need for active scientific monitoring.

The pace of ground deformation and low-level seismic activity has recently increased. — AFP