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 tiny Juan de Fuca plate is largely responsible for the volcanoes ... where plates move into one another; divergent, where plates move apart; and transform, where plates move sideways in ...

St. Helens. Most of the subducting plate continues into the mantle, perhaps to reappear much later at a distant divergent boundary.

This is called a constructive or divergent plate boundary. These are usually found under oceans. As the plate moves apart, magma rises to the surface and cools, forming shallow-sided volcanoes.