making the ridge the longest mountain range in the world. On land, giant troughs such as the Great Rift Valley in Africa form where plates are tugged apart. If the plates there continue to diverge ...

Four types of plate tectonic activity are demonstrated in this feature. Keep an eye on the map to see where in the world the activity takes place. Also known as spreading boundary, a divergent ...

The plates of the Earth's crust are constantly moving at about the same speed as your fingernails grow, so the map of the world will continue to change, but just very, very, very slowly.