Why does continental drift happen?
The continental drift theory has been replaced by the science of plate tectonics. What drives plate tectonics is heat from the interior of the Earth. Heat rises through the mantle outward toward Earth’s surface. In the asthenosphere, there is plastic-like rock and it slowly flows in a current. The current rises to reach the lithosphere (that is its maximum height). The hot mantle rocks melt from the lowering of pressure and rises to form new crust at mid ocean ridges at these points. The tectonic plates on either side move apart as new material is added at the ridges. Eventually, this causes the continents located on the plates to drift apart. The theory also states that one day, due to subduction and the Pacific Ocean shrinking, that there will be another supercontinent like Pangea.
