Scientists have discovered a massive hidden magma system deep beneath Tuscany, revealing that enormous volcanic reservoirs can exist even when there are few clear signs at the surface.
The discovery was made by an international team involving researchers from the University of Geneva, the Institute of Geosciences and Earth Resources, and the National Institute of Geophysics and Volcanology. Their findings were published in Communications Earth & Environment.
Using a seismic imaging method called ambient noise tomography, the researchers identified about 6,000 cubic kilometers of volcanic fluids buried beneath the region. The body lies at depths of roughly 8 to 15 kilometers below the surface.
This volume is comparable to some of the worldโs major volcanic systems. However, unlike well-known volcanic areas such as Yellowstone, Lake Toba, or Lake Taupo, the Tuscany system does not show obvious surface clues such as large volcanic craters, major gas release, or dramatic ground deformation.
The finding shows that very large magma systems can remain hidden within Earthโs crust if they do not produce strong surface signals.
To locate the reservoir, the team used natural vibrations that constantly move through the ground. These tiny signals are generated by ocean waves, wind, and human activity. By recording how seismic waves traveled through the crust, the scientists were able to build a three-dimensional image of the hidden structures below Tuscany.
Seismic waves slow down when they pass through very hot or partially molten material. The researchers deployed about 60 high-resolution sensors and used the changes in wave speed to identify the underground magma-rich region.
Although the system is enormous, the researchers stress that it does not pose an immediate volcanic threat. Over geological timescales, magma bodies of this size can be linked to large volcanic systems, but there is currently no indication of imminent danger.
The discovery is also important for clean energy and resource exploration. Deep magmatic systems can heat underground fluids, making them valuable for geothermal energy. They may also be linked to deposits of lithium and rare earth elements, materials needed for batteries, electric vehicles, and other technologies central to the energy transition.
Because ambient noise tomography can scan large underground regions quickly and relatively cheaply, it could become a useful tool for identifying geothermal reservoirs and critical mineral deposits.
The study highlights Tuscanyโs deep geological complexity and shows how much remains hidden beneath apparently quiet landscapes.
By revealing a vast magma reservoir below the region, the research offers new insight into how volcanic systems develop, how geothermal energy may be located, and how Earthโs hidden heat can shape both geology and future energy resources.
Journal Reference:
Lupi, M., Stumpp, D., Cabrera-Pรฉrez, I., Michailos, K., Saccorotti, G., Bonini, M., Farina, F., Jiwani-Brown, E. A., Lanari, R., Papeschi, S., Savard, G., Porras, J., Sfalcin, J., Muรฑoz-Burbano, F., Minetto, R., Del Ventisette, C., Piccinini, D., & Montanari, D. (2026). High-enthalpy Larderello geothermal system, Italy, powered by thousands of cubic kilometres of mid-crustal magma. Communications Earth & Environment, 7(1). https://doi.org/10.1038/s43247-026-03334-0