Campi Flegrei, the 13-kilometer-wide (8-mile-wide) supervolcano beneath the Bay of Naples, is showing signs of unrest, according to a new study. So perhaps 2016 will literally go out with a bang.
A team of French and Italian geoscientists, including those at the National Institute of Geophysics and Volcanology in Bologna, has concluded that the enormous caldera may be entering a stage wherein it will soon be ready for an eruption, based on the current rate of ground deformation observed at the site.
They have also identified a threshold where, if passed, the supervolcano is likely to commence an eruptive phase. Worryingly, the researchers have concluded that Camp Flegrei’s threshold is being rapidly approached. However, the team warn against making any concrete eruption predictions just yet.
“Additional careful scrutiny of monitoring data in the coming months and years is key,” they write in their study.
Generally speaking, the more trapped gas within a gloopy magma, the more explosive the resulting eruption is. This is because a high gas content increases the pressure inside a magma source, and the greater the pressure difference between the magma and the surface world, the more explosive the resulting decompression will be.
Based on a series of models involving gases and fluids under various pressures, the team have identified something called a “critical degassing temperature” (CDT). This denotes the point at which much of the trapped gas is suddenly released by the magma. When this happens, the surrounding rocks are blasted by superheated gases to a point wherein they may fracture.
These fractures may be significant enough to cause a catastrophic collapse, after which the magma source will explode onto the surface in a powerful eruption. According to recent surface measurements around Naples, Campi Flegrei is approaching the CDT quite quickly, which, of course, is bad news.
Solfatara, at Pozzuoli, is an active geothermal area that is fueled by Campi Flegrei's magma source. Landscape Nature Photo/Shutterstock