An Italian-Swiss team has revealed the presence of 6,000 km³ of magma beneath Tuscany.
An international team has identified a vast reservoir containing approximately 6,000 km
3 of magma beneath Tuscany. Beyond the scientific feat, this advance paves the way for faster and cheaper exploration methods to locate resources such as geothermal reservoirs, lithium, or rare earths, whose formation is closely linked to deep magmatic systems. This work is published in the journal
Communications Earth & Environment.
Illustration image Pixabay
Yellowstone National Park in the United States, Lake Toba in Indonesia, and Lake Taupo in New Zealand: these famous volcanic sites often harbor immense reservoirs of magma, several thousand km
3 in volume, beneath their reliefs. Visible surface clues—such as eruptive deposits, craters, ground deformations, or gas emissions—reveal their presence. However, in the absence of such signs, significant volumes of magma can remain hidden and go unnoticed in the depths of the Earth's crust.
This was precisely the case in Tuscany, where reservoirs containing a total of 6000 km
3 of volcanic fluids, at depths between 8 and 15 km (5 and 9 miles) (middle crust), have just been uncovered by a team from UNIGE, supported by scientists from IGG-CNR and INGV. This magma, which could potentially give rise to a supervolcano in several million years, currently poses no risk.
"We knew that this area, which stretches from north to south of Tuscany, was active in terms of geothermal energy, but we did not know it contained such a volume of magma, comparable to that of supervolcano systems like Yellowstone," explains Matteo Lupi, associate professor in the Department of Earth Sciences (Section of Earth Sciences) at the Faculty of Science of UNIGE, who led this work.
Renowned for its geothermal energy (here the Larderello power plant, the oldest in the world), Tuscany also hides vast magma reservoirs beneath its landscapes, similar to Yellowstone in the United States.
© Matteo Lupi An X-ray of the depths
This molten rock was revealed through ambient noise tomography, a subsurface imaging technique used in seismology. It allows us to "take an X-ray" of the internal structure of the Earth's crust by exploiting natural environmental vibrations, particularly from ocean waves, wind, or human activities.
As these signals penetrate the ground, they are recorded by high-resolution seismic sensors deployed on the surface—about sixty devices in this study. When these vibrations propagate at low speed, they can indicate the presence of molten materials such as magma.
The combined analysis of the recordings made it possible to reconstruct a three-dimensional image of the internal structure of the covered area. "These results are important both for fundamental research and for practical applications, such as locating geothermal reservoirs or deposits rich in lithium and rare earths, used for example in electric vehicle batteries. This work, beyond its great scientific interest, shows that tomography, by exploring the subsurface quickly and at lower cost, can be a useful tool for the energy transition," concludes Matteo Lupi.