These precious stones are buried in the roots of the cratons, the continental masses located between the crust and the mantle, in the lithosphere, at a depth of between 150 and 300 kilometers, according to a joint research by the Massachusetts Institute of Technology and a dozen of universities around the world.
To reach this conclusion, scientists have studied the sound waves that seismographs continuously capture from inside the Earth, reports the scientific news portal Phys.org on Monday.
The sound changes speed depending on the type of rock it crosses. It is known that the cratons are rocks less dense than the rest of materials of the mantle of the Earth, but the scientists had detected that the waves of sound circulate twice as fast in the cratones, than they should.
Experts have resorted to computer simulations, created virtual rocks and used all kinds of rocks and materials inside the Earth, until they found a composition of craton roots that fit with the speed of the sound waves captured by the seismographs.
Finally scientists have concluded that the most feasible combination is that the roots of the cratons have between 1 and 2% of diamonds, which let the sound pass faster than the standard rock of the craton. And this amount is equivalent to almost 10,000 billion tons of diamonds.
It is known that diamonds are created inside the Earth, at high temperatures and pressure, and go out through volcanic eruptions, through rock channels that connect directly with the craton.
However, the human being can not have access to this gigantic wealth with the current technology, since the maximum depth to which man has arrived has been 12 kilometers, through the Kola Superprofound Well, in Russia, and temperatures they already reached 180 degrees of heat.