What is the source of earths internal heat?

Answer 1

The source of the Earth's internal heat is a result of gravitational compression and to a much lesser extent, the decay of radioactive isotopes.

The heat present in the Earth is due to several factors.

The first source of heat is from the remnants of heat from impacts with planetesimals early in Earth's history. Impacts with large bodies such as these (including the impact which led to the formation of the moon) trapped the thermal energy of the collision in the surrounding rock of the planet, and may have been enough in certain circumstances to completely melt the early Earth.

The second source of heat is also a remnant of an early Earth event known as the Iron Catastrophe. With much of early Earth still molten, denser metals, particularly iron and nickel, migrated to the center of the planet. Tremendous amounts of frictional heat was created, enough to completely melt the planet once again.

The third source of heat in the Earth is from compression due to gravity.

The fourth and final source of heat in the Earth is from the decay of radioactive elements. This source of heat is gradually declining due the decreasing amounts of radioactive isotopes, the decrease being caused by the decay.

Answer 2

The heat in the Earth's interior comes from heat produced by the radioactive decay in the mantle. It also comes from the primordial heat left over from the formation of the heat.

Answer 3

the sun

Answer 4

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