Question

Crustal plate movement occurs because the Earth's mantle flows as a result of uneven heating inside the mantle. Convection cells are created by very hot material deep in the mantle rising, then cooling, sinking again, and then heating again and then repeating the cycle. This process occurs because of the energy generated by _________________ within the Earth.

Answer 1

The energy is generated by the semi-molten core of the earth which drives the convection currents in the mantle and which causes the plates to move in plate tectonics. James Hutton was the first geologist to intepret that the plutonic rocks on surface like granite were once molten.

Answer 2

It is because of the radioactive decay of elements.