It is well known that the inner core of the earth is mostly composed of iron (about 85%). The amount of nickel is around 10%. However, the remaining 5% keeps the mystery. The Japanese research team has been looking for this missing element for decades and believes that this part is silicon.
The research team presented its results at the American Geophysical Union (San Francisco), Autumn Meetings.
The earth's solid core is located 3000 km from the surface, and it is thought that the radius is 1200 km. Because it is so deep, it is not possible to directly test it and it is not known exactly which elements of the nucleus are formed (for comparison, the deepest mines of the world can go 4 km deep).
Silicon was thought to be a missing element in a cure. The researchers suggested that the element should be a lighter element and suggested the silicon many times, which was why it was related to its properties and how it was bound to metals.
Instead of drilling, a group of researchers from Tohoku University prepared a prototype miniature Earth (shell, mantle and core) in the lab. It first forms iron and nickel alloys and mixes them with silicon. Then they attached to the large pressure and temperature conditions at the core of the Earth (about 6000 ° C).
These conditions corresponded to the seismic data at the core of the Earth, and the seismic waves emitted from the Earth's center were the data. This reinforced the idea that silicon is the missing element in the team.
Simon Redfern, a professor of mineral physics at Cambridge University, told the BBC: "These tough experiments are exciting because it gives us an idea of what the interior of Earth looks like 4.5 billion years ago. But other researchers have found that oxygen may also be important in the nucleus. "
Knowing precisely what is under our feet allows us to determine the conditions at which the Earth is formed.