Opening details

A few decades ago, a layer several hundred kilometers thick was discovered by seismologists, not much on a planetary scale. At that time, it was believed that the exchange of material between the mantle and the Earth’s core was low. But recently an international team of geologists made a discovery using experimental methods and the Advanced Photon Source, a third-generation synchrotron radiation source at Argonne National Laboratory (USA) and Deutsches Elektronen’s PETRA III synchrotron center. Synchrotron (Germany).

Our experiments […] He found that when water reaches the core-mantle boundary, it reacts with the silicon in the core to form silicon dioxide. This discovery, together with our previous observations of diamond formation from water reacting with carbon in liquid iron under extreme pressure, points to a much more dynamic core-mantle interaction involving significant material exchange.
– says Arizona State University professor Dan Shim.

Thus, as a result of the research, scientists who found that water from the outer layers still reaches the core, concluded that surface water has been transported deep into the Earth for billions of years due to the rise or sinking of tectonic plates. Reaching the core and mantle boundary approximately 2900 kilometers from the surface, this water causes a profound chemical interaction that changes the structure of the nucleus.

Experiments with colleagues from Ense University (South Korea) also helped prove that the reaction of water near the surface of the core creates a hydrogen-rich and silicon-depleted layer, turning the upper outer part of the core into the same mysterious layer. a kind of movie-like structure. And the silica or silicon dioxide crystals discussed earlier rise and sink into the mantle (the layer after the core).

The changing “film” of the core is of great importance to the geochemical cycles that connect surface waters to the planet’s metal core, according to the University of Arizona.