Final answer:
The driving force behind plate tectonics is convection in the mantle, which causes the movement of the Earth's lithospheric plates.
Step-by-step explanation:
The driving force behind plate tectonics is convection in the mantle. The Earth's outermost layer, the lithosphere, is divided into several large plates that float on the semi-fluid asthenosphere. These plates move and interact with each other due to the convection currents in the mantle, which result from the heat generated by radioactive decay in the Earth's core. The convection currents cause the plates to slide, collide, or move apart, leading to various geological phenomena such as earthquakes, volcanic eruptions, and the formation of mountains and oceanic trenches.
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