What is the principle of the heating of the earth's core?

To understand the heating principle of the earth's core, we still have to start with the structure of the earth.

Earth's geological structure

If we can cut the earth into two like cutting a fruit, then we can see that the interior of the earth is divided into circles. The crust is actually the outermost layer of the earth, similar to the skin of a fruit. The average thickness of the earth's crust is about 17 kilometers. The ground in courtyards and parks is the outermost layer of the earth, similar to the skin of a fruit. The average thickness of the earth's crust is about 17 kilometers, and the ground in courtyards and parks is the outermost layer of the earth's crust. If you start digging down from the soil on the ground, you will eventually hit the lithosphere. On land, the main component of the Earth's crust is granite. Below the ocean, the crust is much thinner. From the bottom of the ocean, the crust extends down about 4.8 kilometers and is mainly composed of another rock, basalt.

Below the crust is a deep layer of mantle, which is 2,856 kilometers thick. At present, scientists do not know very much about the mantle layer hidden deep underground, only that the outermost layer of the mantle may be mainly composed of a rock called peridotite. Scientists believe that at least part of the mantle is soft because liquid lava meets the mantle layer on the side near the core.

Finally, it is the center of the earth, the core. It is about 3480 kilometers thick from the outermost layer of the core to the center of the earth. It seems that this place should be colder than the South and North Pole because of the distance from the sun. But in fact, the temperature near the center of the earth is extremely high, about 4000 degrees Celsius. Such a high temperature makes the outer layer of the earth's core liquid, mainly molten metal.

Causes of high temperature in the earth's core

The Earth's core is very dense. Because most of the planet's weight is in the core, the material here is squeezed tightly together. Scientists believe that the enormous pressure turned the Earth's core into a solid iron core. Even though the temperature is high, the huge pressure makes all the iron molecules tightly pressed together, maintaining a solid state macroscopically. The solid metal ball in the center of the earth is about three-quarters of the volume of the moon, and is wrapped in a sea of ​​liquid metal, becoming a planet within a planet.

So where does the heat in the depths of the earth come from? Most of the heat was produced when the Earth formed 4.6 billion years ago—the Earth that formed when smaller objects smashed together gave off heat. But some geologists believe that most of the heat comes from natural radioactive energy deep inside the Earth.

Radioactive elements in the Earth's interior release particles, such as electrons, that collide with atoms in the rock layers, transferring some of the energy to the atoms in the rock, and the rock's temperature begins to rise. In the early days of the earth's formation, these radioactive elements made the rocks inside the earth very hot, and the rocks easily hold heat, so the heat was retained in the earth's interior. Hundreds of years later, the heat inside the Earth is hot enough to melt metals in rocks. Later, the heavy metals were separated from the lighter metals and sank into the center of the earth, forming the core.