Final answer:
The movement of Earth's tectonic plates is primarily driven by convection currents in the mantle, which are a consequence of the heat from Earth's core. These currents cause the mantle to flow, thus moving the tectonic plates through processes such as subduction, where one plate slides under another.
Step-by-step explanation:
One of the mechanisms that causes the movement of Earth's tectonic plates is the convection currents in the mantle. These currents are driven by the heat from the core of the Earth, causing the mantle to flow slowly. This flow of material acts somewhat like a conveyor belt, pushing and pulling the plates in various directions. This motion can result in plates moving apart, colliding, sliding past each other, or one plate subducting under another. Such movements are integral to the formation of mountains, earthquakes, volcanic activity, and the gradual drifting of continents.
For example, when two plates collide, and one plate slides under another, we call this process subduction. The bending and breaking of plates at their edges can lead to significant geological phenomena such as earthquakes, which often occur at the boundaries known as fault zones. Each interaction at plate boundaries is crucial in shaping the Earth's geological features.