Here's why:
* Radioactive Decay: Deep within Earth's mantle and core, radioactive elements like uranium, thorium, and potassium decay. This decay process releases a tremendous amount of heat, which is the primary source of energy for Earth's internal heat engine.
* Convection Currents: This heat causes convection currents within the mantle. Hot, less dense material rises, while cooler, denser material sinks, creating a cycle of movement.
* Plate Movement: These convection currents drag the tectonic plates, which are the rigid outer layer of Earth, along with them. The movement of these plates causes earthquakes, volcanic eruptions, and the formation of mountains and ocean basins.
So, while other factors like the Earth's rotation and gravitational forces play a role, the fundamental driver of plate tectonics is the heat generated by radioactive decay within Earth's interior.
