A team of scientists has proposed a model that explains the character of seismic waves that pass through the earth. According to the study, at the boundary between the outer and inner core, there is a suspension layer that contains iron crystals.
The processes that take place in the Earth's core affect the geological life of our planet, defining the character of the magnetic field and global tectonics.
For several decades, scientists have tried to find an explanation for the fact that the elastic waves that travel deep within our planet slow down as they pass through the lower layers of the outer core.
In addition to this strange behavior, there is a noticeable difference between the way waves are propagated from both sides of the core. In the eastern hemisphere, the velocity is higher than in the western hemisphere, as if the outer surface of the inner core was covered with a viscous material. On the western side, the thickness of the roof is greater.
Scientists from the University of Texas in the United States and the University of Sichuan in China have developed a model that explains the characteristics of seismic wave passing through the nucleus.
The authors of the scientific article, published JGR Solid Earth suggest that, above, the inner core of Earth + is covered by a layer of iron “snow” – tiny particles that form in the liquid outer core and fall onto the surface of the solid interior, forming a layer over 300 kilometers thick.
According to Sputnik news, the researchers compared the formation of iron "snow" in the outer core with the process that occurs within the magmatic chambers, when certain minerals crystallize and deposit at the bottom of the chamber.
"The earth's metal core functions on the principle of the magmatic chamber in the crust," explains Jung-Fu Lin, a professor at the University of Texas who participated in this research.
This layer of sediment is the cause of the deviation of the actual movement of seismic waves from theoretical predictions. The "snow" layer slows down seismic waves, especially in the western hemisphere, where it is thicker.