The land on Earth has not always been separated into the seven continents, at one time a
massive supercontinent, known as Pangaea, covered one-third of Earth’s surface. Additionally,
the supercontinent was surrounded by ocean waters called Panthalassa, much of which were in
Earth’s Southern Hemisphere. Geologists believe that the supercontinent split apart over
millions of years because of the movement of the tectonic plates that form Earth’s crust. In fact,
experts predict that over the next 250 million years the movement of the plates will cause the
seven continents to merge into a supercontinent again.