Wonderful Engineering

Quadrillion Tons Of Diamond Are Hidden In Deep Earth, New Study Concludes

Do you consider diamonds to be unique or valuable or are you among those who already doubt that they are overpriced and overpromoted? If you belong to the second group, then you’d be happy to know that the Big Diamond market has taken another hit. Geologists have discovered by making use of sound waves that an enormous stash of the precious stones is located inside the Earth’s interior – around quadrillion tons!

The study kicked off with an international team of researchers that set out to solve a geological mystery that was long overdue for an explanation. Scientists can easily infer the kind of rocks that constitute the planet by carrying out a seismic activity. The soundwaves that are formed because of the earthquakes or volcanic rumblings travel through different rocks at varying speeds. This helps scientists to learn the kind of rocks that are present.

However, there is one area that doesn’t behave in line with this method; Cratons. It is the oldest and the most immovable slabs of rock that our plant has with its roots going down from the center of the tectonic plates to a depth of about 320 kilometers. You would expect faster sound waves, but the speeds that were being observed were off the charts for the assumed makeup.

Ulrich Faul, an author of the study, said, ‘The velocities that are measured are faster than what we think we can reproduce with reasonable assumptions about what is there. Then we have to say, ‘There is a problem.’ That’s how this project started.’

In order to ascertain what the roots of the Cratons have been made from, the team pulled the data collected by the US Geological Survey and other organizations for coming up with a 3D model of how these waves propagate through the Cratons. The team then simulated sound waves making their way through a wide variety of various combinations. The only combination that matches the speeds obtained features a diamond content of 1-2% while the rest features peridotite and minute quantities of eclogite.

When you consider the mass of the cratons on Earth, this little amount comes out to be about a quadrillion tons – almost 1,000 times the quantity of diamond that was known to exist till date. Faul says, ‘This shows that diamond is not perhaps this exotic mineral, but on the [geological] scale of things, it’s relatively common. We can’t get at them, but still, there is much more diamond there than we have ever thought before.’

The research has been published in the journal Geochemistry, Geophysics, Geosystems.