Continental Drift

Abstract The old notion that continents have drifted apart over geological time was revived by the scientific revolution of plate tectonics in the 1960s. Geologists now believe that the Earth's crust is made up of about 20 tectonic plates which are constantly shifting with respect to one another at a rate of centimetres per year. These plate motions and interactions are responsible for most of the Earth's volcanoes, earthquakes, mountain belts, and many other geological phenomena.