Global tectonics. Satellite-based artwork of an Earth globe centred on the Australian Plate. This is one of the seven primary tectonic plates that make up the Earth's crust. 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 the millions of years of geologic time drives the creation, destruction and drifting of the continents. The movement of the tectonic plates is thought to be driven by convection currents in the underlying mantle.