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Sources of heat inside the Earth


A lot of heat is required to transform the structure of the rocks inside the earth. Heat can either melt the rocks or transform their crystalline structure without melting (metamorphism). Pressure also plays a key role in this process

The heat inside the earth is generated mainly by the decay of radioactive elements such as uranium, thorium and potassium. The high-speed fragments of the broken nucleus heat the mantle by friction . Uranium emits high-energy alpha particles and their kinetic energy is degraded into heat. Strictly speaking, chemical reactions don't produce heat directly. After a collision between molecules, a lot of the the energy of each molecule is stored in the vibrational and rotational movements ( modes ). This energy will degrade into heat (kinetic energy of the fragments) in a fraction of a second.

Other source of heat is the movement of the tectonic plates,, which are pieces of crust that float on top of the magma (molten rock material found inside the Earth), and squeeze rocks and also heats them by friction . Convection currents move materials around the interior of the planet and also affect the tectonic plates On the boundaries of these plates we observe volcanic activity and earthquakes and these processes bring rocks and other material to the surface.