How does earth's core work?

Question

Leah Abbate · Accepted Answer

The heat comes from the formation of the Earth, radioactivity and friction as it drags dense materials down with gravity. The iron-nickel alloys in the core also produce the Earth's magnetic field.

In the early solar system's history, small particles floating in space began to attract each other and clump together, gaining mass which in turn caused more gravity which in turn caused more attraction. The ball of stuff would grow, pushing denser materials into the center, or core, and lighter elements remaining around the outside as the crust. This is why the core is now a huge lump of iron, while the crust is primarily silicon, oxygen, and carbon. The Earth was most likely formed by core accretion. Even though the inner core of the Earth is 5700K, far above the melting point of regular iron, the pressure from the weight of the rest of the Earth is so great that the core is forced into a solid state. Part of the heat emanating from the Earth's core is residual energy from the planet's accretion, which is released gradually and heats the planet from the inside out. In addition, there is frictional energy because dense materials are still being drawn towards the core by gravity, albeit more slowly now that there is so much more material in the way. This means that there is a significant amount of gravitational energy that can be converted into kinetic, frictional, and most importantly, heat energy. Ultimately, the majority of Earth's heat comes from radioactive elements found in the core and mantle, such as uranium and thorium, which decay and release a great deal of energy. Earth's magnetic field is also believed to originate from the core. The outer core, which is still fluid, is composed of the magnetic metals iron and nickel. These alloys flow and cause the Earth's magnetic field to be moved, which is why geophysicists predict the Earth's magnetic fields will eventually flip.

Hazel Asher · Answer

undefined The Earth's core is made up of two parts: the outer core, which is primarily made of liquid iron and nickel, and the inner core, which is a solid ball of iron and nickel alloy. The heat from the Earth's formation and radioactive element decay keeps the outer core molten, and the movement of conducting materials, mostly liquid iron, in the outer core creates the Earth's magnetic field, a phenomenon known as the geodynamo effect.