The latest episode of MinuteEarth (previously) presents a simple explanation of the science behind plate tectonics, which is behind continental drift and creates mountain ranges and earthquakes.
The common, simplified explanation for why tectonic plates are moving is that they’re carried along on currents in the upper mantle, the slowly flowing layer of rock just below Earth’s crust. Converging currents drive plates into each other, diverging current currents pull them apart. This is mostly true.
