The accepted theory explaining the constant, slow movement of the Earth’s major tectonic plates identifies the principal driving force originating deep within the planet’s interior. What is this primary mechanism responsible for plate drift?

💡 Explanation:

The primary mechanism driving plate movement is mantle convection, specifically the slow circulation of heat and material (thermal convection cells) within the asthenosphere (the upper, ductile layer of the mantle). This circulation creates drag on the overlying lithosphere (tectonic plates), causing them to move. While ridge push and slab pull also contribute significantly, convection provides the fundamental energy source and large-scale movement mechanism.