Why does Earth have plate tectonics?
Heat! When you take a cake out of the oven, it slowly cools. Earth, and the other terrestrial planets, started out very hot. Through time, they have cooled. The heat from the interior is slowly transported from the center to the surface, where it is lost from Earth. In Earth’s case, much of this transfer occurs by a process called convection. Hot material rises from the interior of the Earth, carrying the heat with it. It rises because it is less dense than the cooler material around it. As it gets close to the surface, the material cools — releases its heat — and slowly descends back toward the center, where it heats up and rises again. While Earth’s interior is hot, most of it is not molten! Rock under high pressures and temperatures — such as those found in Earth — can slowly flow. The convection currents in Earth’s interior move the rigid plates across Earth’s surface. Tectonic deformation and earthquakes mostly occur at the boundaries between these plates. Are there tectonics on o
