Russian dolls
Article reserved for subscribers
According to a study published by two seismologists from the Australian National University, the center of our planet would have an additional layer: a metallic ball 650 kilometers in diameter.
The time is approaching when the SVT textbooks will have to be rewritten… Because it seems that the core of the Earth has an additional layer. It is not simply composed of a liquid envelope (the “external core”) and a solid heart (the “internal core”), but it would contain at the very center a metallic ball approximately 650 kilometers in diameter with a different structure from the inner core. A scientific study, published on February 21 in the review Nature Communications, brings new evidence to this idea that has been gaining ground for a few years: there is one last figure in the land Russian doll game.
Thanh-Son Pham and Hrvoje Tkalcic are two seismologists from the Australian National University, Canberra. They study the inner core of the Earth to better understand the magnetic field that surrounds and protects our planet – because it is the movements of heat in the core that create convection currents and generate this magnetic field. But because it is tiny (less than 1% of the planet’s volume) and inaccessible (more than 5,000 kilometers deep), the inner core cannot be studied directly. Information regarding its size, composition and structure is gathered by listening to the shock waves passing through it following an earthquake. The speed of seismic waves depends on the density and temperature of the mats
