All the Earth's land had once been joined into a single supercontinent surrounded by the ocean. Alfred Wegener, a German meteorologist and polar explorer proposed this theory. He called the supercontinent Pangea. He believed Pangea had been broken into pieces about 200 million years ago. The pieces started moving into their present positions and are still on the go.

He said that the heavy continents were slung toward the equator on the spinning Earth by a centrifugal effect. This inertia, coupled with the tidal drag on the continents from the combined effects of sun and moon, would account for the phenomenon of drifting continents.

- Wegener seemed to have only used evidence of the drifting that would be good for his theory.
- Where did the wakes or tracks through old seabed that the migrating continents would leave came from?