Why do South America and Africa seem to fit together like puzzle pieces? Why do volcanoes and earthquakes cluster in belts that girdle the globe? Why are all the ocean basins extremely young? Plate tectonics — the unifying concept of geology answers these questions and many others by explaining the dynamic motions and interactions of Earth’s tectonic plates. Find out how scientists fit together the pieces of the plate-tectonic puzzle.
Some of the clearest images of the ocean floor come from space! This one of the Atlantic Ocean was made by a satellite that can detect subtle differences in the height of the ocean surface. Amazingly, the height reflects the topography of the sea floor.