At divergent boundaries, plates move away ... of a region of distributed deformation. This process permits a significant reorganization of the plate motion. The fluids also trigger mantle melting ...

These convergent boundaries also occur where a plate of ocean dives, in a process called subduction ... build up into island arcs like Japan. At divergent boundaries in the oceans, magma from ...

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.

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

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 ...