SOLAR SYSTEM

Detailed explanation-1: -The movement of these tectonic plates is likely caused by convection currents in the molten rock in Earth’s mantle below the crust.

Detailed explanation-2: -The primary sources of thermal energy for mantle convection are three: (1) internal heating due to the decay of the radioactive isotopes of uranium, thorium, and potassium; (2) the long-term secular cooling of the earth; and (3) heat from the core.

Detailed explanation-3: -Mantle convection occurs because relatively hot rocks are less dense and rise in a gravitational field while relatively cold rocks are more dense and sink. The rise of hot rocks advects heat upward while the fall of cold rocks advects cold downward; this counterflow is equivalent to an upward heat flux.