A volcano in the south of Italy could be coming closer to erupting, putting the lives of more than half a million people in danger, an article from Nature Communications has warned.
Scientists believe that magma at the Campi Flegrei volcano in Naples is reaching a level designated by "critical degassing pressure" (CDP). This is characterized by sudden release of water-rich gases in vast volumes, which could lead to rock failure and explosion of the volcano, the report, released late last month, said.
"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," the eight scientists said in the report.
There have been some reawakening signs in Campi Flegrei since the 1950s, from some low earthquake activity to hydrothermal degassing, with a pause in early 2000s. But in 2005, there were new uplifts and further activity has been recorded.
"However, it is not clear whether this unrest will culminate in an eruption and if it does over what timescale this will occur," the scientists said, adding that this represents a challenge for local authorities when trying to protect the population.
In 2010, volcanic activity in Iceland led to the closure of airspace in some European countries as it was feared ash from the Eyjafjallajokull volcano would damage aircraft engines.
Last June, a rumbling volcano in the Philippines also affected aviation and the government banned hiking.
Italy has several active volcanoes and the region of Naples is relatively prone to seismic activity. In 79 AD, the eruption of Mt Vesuvius in the Gulf of Naples led to the destruction of Pompeii and Herculaneum. Follow CNBC International on Twitter and Facebook.