Scientists have discovered a reservoir of water three times the volume of all the oceans below the Earth’s surface, according to an international study. Water has been found between the transition zone of the upper and lower mantle of the Earth. The research team analyzed a speed diamond formed 660 meters below the Earth’s surface using techniques including Raman spectroscopy and FTIR spectrometry, ANI reported.
The study confirmed something that was long just a theory, namely that ocean water accompanies subducting slabs and thus enters the transition zone. This means that our planet’s water cycle includes the interior of the Earth.
“These mineral transformations greatly hinder rock movements in the mantle,” explains Prof. Frank Brenker of the Institute for Geosciences at Goethe University Frankfurt. For example, mantle plumes, rising columns of hot rock from the deep mantle, sometimes stop directly below the transition zone. Mass movement in the opposite direction also stops.
Says Brenker: “Subducting plates often have a hard time traversing the entire transition zone. So there is a whole graveyard of such plates in this zone under Europa.”
However, until now it was not known what the long-term effects of the “suction” of material in the transition zone were on its geochemical composition and whether larger amounts of water existed there. Brenker explains: “Subduction slabs also carry sediments from deep seas on slopes into the Earth’s interior. These sediments can contain large amounts of water and CO2. But until now it was unclear how much enters the transition zone in the form of more stable, hydrated minerals and carbonates, and therefore it was also unclear whether large amounts of water are actually stored there.”
Undoubtedly, the prevailing conditions would be conducive to it. The dense minerals wadsleyite and ringwoodite can (unlike olivine at shallower depths) store large amounts of water, so large in fact that the transition zone could theoretically absorb six times the amount of water in our oceans. “So we knew that the boundary layer has an enormous capacity to store water,” says Brenker. “However, we didn’t know if he actually did it.”
An international study in which the Frankfurt geoscientist was involved has now provided the answer. The research team analyzed a diamond from Botswana, Africa. It was formed at a depth of 660 km, right at the interface between the transition zone and the lower mantle, where ringwoodite is the predominant mineral. Diamonds from this region are very rare, even among the rare diamonds of super-deep origin, which make up only one percent of diamonds. Analysis revealed that the stone contains numerous ringwoodite inclusions, which exhibit a high water content. In addition, the research group was able to determine the chemical composition of the stone. It was almost exactly the same as virtually all mantle rock fragments found in basalts anywhere in the world. This showed that the diamond definitely came from a normal part of the Earth’s mantle. “In this study, we have shown that the transition zone is not a dry sponge, but rather contains considerable amounts of water,” says Brenker, adding: “This also brings us one step closer to Jules Verne’s idea of an ocean.” inside the Earth.” The difference is that there is no ocean down there, but rather hydrated rock that, according to Brenker, would not feel wet or drip water.