A volcanic area comprised of 24 craters and volcanic edifices along the Italian coast — much of it underwater — is showing signs of reawakening after a long period of inactivity.
Campi Flegrei is infamous for its previous eruptions. Its first eruption occurred around 200,000 years ago and triggered a "volcanic winter." The second eruption occurred around 39,000 years ago and was so massive that some hypothesize it was a factor in the extinction of the Neanderthals.
A third smaller eruption occurred in 1538 when eight days worth of activity formed the 1,503-foot-high Monte Nuovo mountain. (Yes, that was considered "small" for Camp Flegrei.)
New research shows that recent unrest since the 1950s has had a cumulative effect, leading to a build-up of energy in the crust and making the volcano more susceptible to an eruption.
“By studying how the ground is cracking and moving at Campi Flegrei, we think it may be approaching a critical stage where further unrest will increase the possibility of an eruption, and it’s imperative that the authorities are prepared for this,” Christopher Kilburn, director of the UCL Hazard Centre, said in a statement.
The new study, published in the journal Nature Communications, points out that an eruption is not necessarily imminent, but may be closer than previously thought
When this supervolcano decides to awaken, it historically does so with a devastating roar. So when Campi Flegrei began showing signs of life in recent years, scientists shifted their attention accordingly.
Science Alert reports:
Now a team led by volcanologist Giovanni Chiodini from the Italian National Institute of Geophysics in Rome reports that Campi Flegrei appears to be approaching a critical pressure point that could trigger another eruption. This critical pressure point — referred to as critical degassing pressure (CDP) — could drive volcanic unrest towards a critical state, the team reports, by releasing jets of super-hot gas into the atmosphere, heating the surrounding hydrothermal fluids and rocks, and causing rock failure and possibly an eruption.
"Hydrothermal rocks, if heated, can ultimately lose their mechanical resistance, causing an acceleration towards critical conditions," Chiodini told the AFP. Over the past decade, Campi Flegrei has be experiencing an 'uplift,' which suggests that the volatile gases beneath it are rising to the surface at an accelerating rate. In response to this uplift, Italy raised the supervolcano's alert level from green to yellow — or from "quiet" to "requires scientific monitoring."
Two other active volcanoes, Rabaul in Papua New Guinea and Sierra Negra in the Galapagos, "both showed acceleration in ground deformation before eruption with a pattern similar to that observed at Campi Flegrei," Chiodini said.
It's impossible to predict if and when the supervolcano might erupt. But that just makes it all the more important for researchers to monitor the activity closely. An eruption now would affect not only the roughly 500,000 people living near it, but could potentially affect the entire planet.
You can learn more about the volcano in the video below:
Editor's note: This story has been updated since it was published in December 2016.