A vast reservoir containing approximately 6,000 cubic kilometers of magma has been identified beneath Tuscany by a scientific team from the University of Geneva, the Italian Institute of Geosciences and Earth Resources, and Italy’s National Institute of Geophysics and Volcanology. The study was published in the journal Communications Earth & Environment.

Large underground magma reservoirs are also found beneath areas such as Yellowstone National Park in the United States, Lake Toba in Indonesia, and Lake Taupo in New Zealand. Their presence is typically revealed through surface indicators such as craters, ground deformation, and gas emissions. However, in the absence of such signs, large volumes of magma can remain hidden within the Earth’s crust.

This was the case in Tuscany, where scientists discovered magma reservoirs at depths of 8–15 kilometers within the crust. While this magmatic body could theoretically contribute to the formation of a supervolcano, it does not currently pose any danger. “We knew that this region, stretching from north to south across Tuscany, is geothermally active, but we did not realize it contains such a large volume of magma, comparable to that of supervolcanic systems like Yellowstone,” explained the study’s lead author, Matteo Lupi, associate professor in the Department of Earth Sciences at the University of Geneva.

The magma was detected using ambient noise tomography, a subsurface imaging technique widely used in seismology. The method relies on natural environmental vibrations generated by ocean waves, wind, or human activity. As these signals travel through the ground, they are recorded by high-resolution seismic sensors installed on the surface. Around 60 instruments were used in this study. When seismic waves travel at unusually low speeds, it can indicate the presence of molten material such as magma.

By combining and analyzing the recorded data, researchers reconstructed a three-dimensional image of the region’s internal structure. They note that this method is significant for enabling fast and cost-effective subsurface exploration.

The photo depicts geothermal activity in Larderello, Tuscany.