The earth's interior heat and pressure drive mantle convection. This is the power that drives plate tectonics, the main force behind earthquake and volcanic activity.
The convection currents in the mantle, are having very high temperatures and very high pressures. Because of that, they managed to crack the crust, and thus divide the surface of the Earth in multiple peaces, or as we call them, tectonic plates. The very high pressure from bellow manages to push the tectonic plates in certain direction, and even though that movement is only a couple of cm per year, on the long term it has huge effects on everything on the planet.
