Earth's interior heat comes from two main sources: residual heat left over from the planet's formation and ongoing radioactive decay within Earth's core and mantle. This heat keeps the outer core liquid through convection of iron and nickel, generating the Earth's magnetic field, and drives thermal convection in the mantle which powers plate tectonics at the surface. Heat is eventually released through volcanic and tectonic activity that forms and cools new crust.

1. Earth’s Interior Heat

2. What is heat?
• A type of energy related to kinetic energy or movement of
atoms
• More/faster movement of atoms more heat

3. Two Sources of Heat
• 1. Residual Heat – thermal
energy left over from the
formation of Earth via
bombardment and accretion

4. Two Sources of Heat
• 2. Radioactive Decay – the
release of energy and
energetic particles from
radioactive materials heats up
surrounding particles

5. What effect does the heat have on the outer
core?
• Keeps it liquid
• Causes convection of iron/nickel
• This results in Earth’s magnetic field

6. What effect does the heat have on the
mantle?
• Causes thermal convection in the mantle which in turn drives
plate tectonics

7. Where does the heat eventually go?
• The heat is released at the Earth’s surface where new crust is
formed and cooled