Scientists have discovered a very large area of hot, melted rock deep under the Tuscany region of Italy. This magma reservoir is located between 8 and 15 kilometers below the surface and is about 6,000 cubic kilometers in size. This makes it as large as the magma systems found under famous supervolcanoes like Yellowstone in the United States.
Although the reservoir is huge, researchers say it does not pose an immediate danger to people living above. The area does not have the large craters associated with supervolcanoes, and the ground has not moved much. The last volcanic activity in the area was a small eruption at Mount Amiata about 300,000 years ago.
An international team used special listening equipment with about 60 seismic monitors to find the magma. They used a method called ambient noise tomography, which listens to small vibrations in the Earth caused by ocean waves and human activity. When these vibrations travel through magma, they slow down. The scientists noticed the vibrations slowed by 30 to 40 percent, allowing them to map the underground area.
This discovery helps explain why the area around Larderello has been known as "Devil's Valley" for a long time, famous for its natural steam vents. The heat from the magma system below powers geothermal electricity plants that have been operating since the early 1900s. The Larderello part of the reservoir alone contains about 3,000 cubic kilometers of melted rock.
Scientists believe a dangerous eruption is unlikely because the magma is very thick and did not come from deep within the Earth. Instead of being a threat, this discovery could be valuable for finding rare earth elements and lithium, which are important for making batteries for electric cars and renewable energy technology. The research also shows that this listening method is a fast and affordable way to explore underground resources.