Our planet is overflowing with water, according to an international group of scientists, only it is not stored everywhere in liquid form.
So, according to their hypothesis, at a depth of 410 to 660 km below the earth's surface, the layer that separates the upper and lower mantles contains approximately the same amount of water as in the World Ocean, i.e. about 1340 million km3. The water in the Earth's mantle is not in the liquid state we are used to - it is "locked" in mineral crystals in the form of ions.
To verify the validity of their assumptions, scientists conducted laboratory experiments on synthetic rocks that are used to simulate the deep layers of the planet. Geophysical and seismic measurements show that the viscosity of the transition zone of the mantle is lower than that of the upper mantle. Experiments have shown that the viscosity values in this area coincide with those of non-synthetic rocks; the volcanic mineral of the olivine group - ringwoodite - is quickly saturated with water. This suggests that the transition zone of the mantle is wet, not dry.
The huge amount of water trapped inside the mantle certainly leads to the thought of how it got there? Or has it always existed there after the mantle solidified? This is a key issue in the evolution of the Earth that extends to other planets outside of the solar system.