Due to its metallic nature, the liquid outer core is the ** of the Earth's magnetic field, which means it contains electrons that are not attached to a particular nucleus. The heat is transferred up the mantle from the inner core to the mantle by convection chambers, and the liquid in the outer core flows in a circulating pattern. The combination of loose electrons and cyclic convection with the Earth's rotation creates a geogenerator that generates a magnetic field. Since the magnetic field is generated by dynamic convection and rotating liquid spheres, it is unstable.
Sometimes, after hundreds of thousands to millions of years, the Earth's magnetic field becomes unstable or even temporarily shut down. According to the physics of the magnetic field spontaneously generated by the earth rock, when it restarts, its north and south magnetic poles are bound to be reversed. (In contrast, the Sun's magnetic field is also generated by the convective charge in the rotating sphere, and its magnetic force becomes unstable and reverses its magnetic field more regularly every 11 years.) ）
Given that the core is a solid metal ball, mostly made of iron and nickel, completely surrounded by liquid, it can be imagined as a giant ball bearing rotating in a pressurized fluid. A detailed study of the ** wave that passes through the inner core has found that it rotates only slightly faster than the rest of the Earth.
The Earth's interior is not simply layered. Some layers, especially the crust and lithosphere, vary greatly in thickness. The boundaries between layers are rough and irregular. Some layers penetrate other layers at certain locations. The dynamic nature of the Earth is reflected in the variation of the thickness of the Earth's layers, the irregularities of the boundaries of the layers, and the interpenetration of the layers.
For example, the lithosphere penetrates deep into the mesosphere in the subduction zone. Although this is still a matter of research and debate, there is some evidence that subducted plates may permeate all the way down to the lower mesosphere. If so, then plate tectonics is causing extensive mixing and exchange of materials in the Earth, from the bottom of the mantle to the top of the crust.
As another example, hot spots could be where gases and fluids rise from the core-mantle boundary along with heat. Studies of helium isotopes in hot volcanic rocks have found evidence that most of the helium comes from deep within the Earth, possibly from the lower middle layer.
We humans cannot get our own samples of the Earth's interior from deeper than the upper mantle. The density and depth of the Earth's core is completely inaccessible. Contrary to popular misconception, lava does not come from the center of the earth. Magma and lava come only from the lithosphere and asthenosphere, i.e. the upper 200 kilometers of the Earth's thickness of 6,400 kilometers. Attempts have been made to drill through the earth's crust to reach the mantle, but without success.