The geography of the world changes over the course of millions of years due to the motion of Earth's tectonic plates. Continents are pushed across the surface of the Earth; they join; they split apart. On shorter time scales continents can be joined or separated by changes in sea level. The true boundary between continental lithosphere and ocean basin is the edge of the continental shelf. Currently, many continents have broad continental shelves--areas of submerged continental lithosphere. This means that relatively small changes in sea level can have a major effect on the geography of a continent.

Discovery Topics > Sea Level Change > Global Sea Level Change <