What causes the movement of tectonic plates?

• A. The rotation of Earth on axis
• B. The convection current in the mantle
• C. Weather patterns in the atmosphere
• D. Ocean waves

Answer: (B)

The movement of tectonic plates is driven by convection currents in the mantle. Heat from Earth's interior creates slow, circular flows inside the mantle: hot material rises, spreads out beneath the lithosphere, cools, and sinks again. This flowing mantle drags the rigid tectonic plates resting on top of it, causing the continents and ocean floors to slowly shift over time. That convection-driven motion explains why new crust forms at mid-ocean ridges and why older crust sinks at subduction zones.

The other options don’t move plates because Earth’s rotation affects overall spin and Coriolis effects but doesn’t push plates across the surface; weather patterns in the atmosphere and ocean waves influence surface conditions and erosion, not the deep-seated movement of the lithosphere. The key force behind plate motion is the mantle’s convection currents.