Volcanoes and Plate Boundaries

Most of the Earth's volcanoes are located at tectonic plate boundaries. These volcanoes are found on both continental and oceanic crust.

The belt of volcanoes along the boundary of the Pacific Ocean is called the Ring of Fire because it contains about 75% of the world's active volcanoes.

Mid-ocean ridges form from lava pouring onto the ocean floor at divergent plate boundaries. On land, divergent boundaries produce chains of active volcanoes.

At convergent boundaries, oceanic plates are subducted and magma forms from melting crust. Eruptions create volcanic island arcs in the ocean and volcanic mountain ranges on land.

Some volcanoes form over hot spots that are not located along plate boundaries. A hot spot occurs when rising magma is close to the Earth's surface. The islands of Hawaii were formed over a hot spot in the Pacific Ocean.