Researchers from the University of Geneva and various Italian scientific institutions published a study that transformed the geological perception of Europe. The team detected a huge magma deposit in the middle crust, which remained hidden under the mountains of a region famous for its tranquility and its renewable energy industry.
This finding focused on the Magmatic Province Tuscanyan area where the Larderello-Travale geothermal system stands out as the main axis of thermal activity. Despite the absence of volcanic eruptions in recent historical times, new subsurface data revealed the existence of fluids at extreme temperatures at very shallow depths.
The scientists estimated that more than 5,000 cubic kilometers of magma and molten material They are stored in the crust of this region. «Such volumes are comparable to those of mid-crustal reservoirs under recognized supervolcanoes,» stated the authors of the study published in Communications Earth & Environment.
The research compared this system with geological colossi of the size of Yellowstone in the United States, Toba in Indonesia and Taupo in New Zealand. According to the document, the identification of structures of this magnitude without eruptive evidence on the surface represented a unprecedented technical challenge for the geological community.
The technology that revealed the secrets of the underground
To obtain this detailed x-ray of the subsoil, experts installed a network of more than 60 broadband seismometers between 2020 and 2021. This infrastructure allowed the application of a technique called Environmental Noise Tomographywhich reconstructed the speed of seismic waves up to 15 kilometers deep.
The test results indicated that, from 8 kilometers deep, the speed of the waves drops drastically, which indicated the presence of molten rock. The specialists explained that this phenomenon was linked to massive magmatic reservoirs that feed the extreme heat of the area.
A discovery that surprised the scientific community
A fact that astonished the scientific community was the temperature recorded in previous drillings in the area. In the Venelle 2 well, technicians reached the 512 degrees Celsius at a depth of just 2.8 kilometers, a fact that confirmed the proximity of a colossal heat source.
The region, which in ancient times was called «Devil’s Valley» Due to its fumaroles and sulfur deposits, it kept this geological secret for millennia. Geologists noted that the high viscosity of the local peraluminous magma functioned as a natural plug that prevented large eruptions in the past.
Under the sector Mount Amiatathe deposits of molten material showed dimensions that could even double those of Larderello. The research team stressed the importance of carrying out new seismic studies to specify the total volume of magma in that southern part of Tuscany.
This discovery provided the first quantitative constraints on the location and size of magma in the region and closed historical debates about the origin of heat in the region. Tuscany. The experts concluded that the discovery was critical to understanding the evolution of magmatic systems and the risks associated with these invisible reservoirs.
