Earth's tectonic plates, illustration. There are seven primary tectonic plates that make up the Earth's crust. At centre are the smaller Cocos (left) and Caribbean (right) plates, surrounded by (clockwise from top) the North American, African, South American, Nazca, and Pacific plates. Phenomena observed at the boundaries (red) between these plates include earthquakes, volcanic activity, mountain-building, and oceanic trench formation. The movement of the tectonic plates over millions of years of geologic time drives the creation, destruction and drifting of the continents. The movement of the tectonic plates is driven by convection currents in the underlying mantle.