Heat Transfer

There are 3 types of heat transfer:

• Radiation: Radioactive decay accounts for half of Earth's heat. Elements such as uranium and thorium split into smaller atoms and end up giving off heat as they decay. This takes place in the Inner Core.
• Conduction: The process of heat transfer through touch. Heat is transferred from the Inner Core to the Outer Core through conduction because they are touching.
• Convection: The transfer of heat by moving fluids. Hot fluids rise (because they become LESS DENSE) and cold fluids sink (because they become MORE DENSE). This occurs in the layer of the mantle called the Asthenosphere.

The tectonic plates sit on top of these giant convection cells and end up getting dragged in the same direction. The image below shows an example of plates moving with their underlying convection cell.

Disclaimer: THE SUN HAS NOTHING TO DO WITH THIS! DON'T BE FOOLED BY THE STUPID SUN!