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There are many studies that prove that under our feet, deeper than the bottom of our seas and oceans , there are big water reservoirs . Even more than on the surface. Many are the evidences that the fluid element is “embedded” in the minerals of the mantle , especially in the transition zone, between 400 and 700 km depth. But, from here, the Earth becomes a relatively “dry”. However, a new study ensures that there would still be more water hidden in the interior of our planet. Specifically, in the core , which could house the equivalence of five oceans in its interior .
The research, led by Yunguo Li , associate researcher at the faculty of Mathematics and Physics at University College London, has just been published in the journal “Nature Geoscience” and could be a revolution not only in order to learn how much water is home to the planet, but what were its origins. “There are still large uncertainties, but it is certain that there is more water below the surface. Our study indicates that the kernel is the largest reservoir of water on Earth , ” says Li to ABC, which explains that this liquid would be present in the atoms of the solute , “diluted” in the cast iron core . However, the major drawback of this theory lies in the fact that, contrary to what happens with the mantle, it is impossible to obtain a sample in the center of the earth. At least, for the time being.
Recreating the beginning
“In the laboratory, scientists have tried to simulate the environment of the formation of the nucleus, but until now, the pressure is much lower that that condition and the findings seem contradictory,” argues the researcher. Recreate the origin of the formation of the nucleus in this primary stage could be the key the presence of water not only here, but in the rest of the planet.
The amount of water that is in the core depends essentially on two factors: one is the partition coefficient of the water between the core material and the material of the mantle. That is to say, where ‘prefers’ to go in the water : if the minerals as the ringwoodita, that are quite soluble and which populate the mantle ; or liquid iron of the kernel. On the other hand, it also depends on the amount of water present during the process of separation between the core and the mantle, a phase that was given at the beginning of the creation of our planet. Currently, there are two theories: one that says that came aboard comets and asteroids during the “ Great Bombardment ” occurred more than 3,000 million years ago; and another, completely opposite, which argues that our planet has had since the time of its formation or was able to make it by means of geological processes.
So, for the first question, the british team calculated the distribution of water between the iron and the silicate fused at high pressures and temperatures, using techniques of molecular dynamics and integration thermodynamics . That is to say, the “preference” of the water by one or other of these materials. “ The water prefers the fusion of the silicate on the solid minerals . That is to say, the water also prefer to go to the core on the minerals of the mantle, as the ringwoodita”, they write in their article. In addition, they determined that most of the water would have gone to the nucleus during division of the Earth’s interior. “Besides, the plates of subduction flush water, which also enters the nucleus,” explains Li. It is like the study demonstrates that the nucleus must have “an appreciable amount of water”.
The exact amount of oceans
Li and his team say that their research points out that “when the core began to separate from the mantle in the form of liquid iron, the greater part of the water present during that process was drawn to the bags of liquid iron and sank to form the core “. However, the question of how much water there is down there is still a question without response.
“Our study cannot give a definitive answer. Depends on the model of accumulation of the Earth: how much water had come to Earth before the separation between the core and the mantle,” admits the researcher. “But according to the studies of isotopes to the most recent and the model of accretion of the Earth, there can be most of the five oceans in the core “. The same amount of water that surrounds the continents can be hidden in the bottom of the earth.