The sound of the sea solves a mystery of decades of supervolcan

Scientists have used the sound of the sea to discover the route taken by the hot fluids that feed a supervolcan in southern Italy.

Using an innovative technique that uses "snoring" – or seismic noise – waves breaking on the coastline of Campi Flegrei, scientists have produced a seismic image of the deeper structure of the volcano that reveals the main pathway that drives the hot fluids on the surface.

Their research appeared in a documentary entitled "The Next Pompeii" on Nova, a well-known scientific series about the great American broadcaster PBS. The documentary highlights the innovative scientific techniques used to monitor Campi Flegrei – a volcanic caldera west of Naples that erupted five centuries ago.

The region has been relatively calm since the 1980s, when the injection of volcanic materials into the shallower structure of the volcano caused thousands of small earthquakes, followed by 38 years of relative silence.

Seismic imaging is one of the main methods used by scientists to accurately map the structure of a deep volcano. However, the low level of seismic activity in the region for nearly four decades has meant that the internal structure of Campi Flegrei has remained a mystery – until now.

The so-called "food pathway" discovered by scientists would have been formed during the last period of seismic activity in the 1980s and would convey volcanic materials from the depths of the volcano at sea.

The material then ascends and follows established routes under the volcano towards fumaroles at Solfatara and Pisciarelli – located approximately in the center of the caldera – where they are expelled as steam through ventilation holes.

Seismology teachers Luca De Siena, Carmelo Sammarco and David Cornwell led the study at the School of Geosciences at the University of Aberdeen. They worked alongside the Observatory of Vesuvius, which informs the Department of Civil Protection of the Italian Government of the threat that volcanic activity represents in the region.

Professor De Siena, now at the University of Mainz, said: "By using noise at the seaside to create a seismic image, we finally have a better idea of ​​how volcanic materials are moving from depths of the volcano up to the surface ",

"This is the first time this relatively new technique has been used in a highly populated area. It shows that the food chain created in the early 1980s seems fully operational in 2011-2013, when we collected the data.

"This is important because it improves our understanding of the character of the volcano, which could possibly improve surveillance and early warning procedures in a region inhabited by millions of people."