An international team of researchers led by scientists from the Bavarian Research Institute of Experimental Geochemistry and Geophysics at the University of Bayreuth has found that an ancient reservoir of water, preserved since the formation of the Earth, may be stored 2,900 kilometers beneath the planet's surface, according to infohub.kz.
To test this hypothesis, the specialists reproduced the extreme conditions of the lower mantle in the laboratory. Using diamond anvils and lasers, they compressed samples under pressure two million times greater than atmospheric pressure and heated them to 2,500 degrees Celsius.
The experiment produced two previously unknown iron oxyhydroxides. According to the authors, it is these compounds that are capable of retaining water at the boundary between the mantle and the core.
Analysis showed that dense mineral compounds can form even with a minimal presence of hydrogen. As noted by Leonid Dubrovinsky, one of the study's authors, these minerals are ideal candidates for the long-term retention of both primordial water and moisture drawn deep into the Earth by the movement of tectonic plates.
The results of the work have been published in the journal Nature Geoscience. They help to better understand the water cycle and the evolution of the Earth's internal structure. Although the experiment was conducted in a laboratory, it provides important clues about exactly where the planet hides its ancient water reserves.