Most volcanoes are found along plate boundaries. This may include convergent boundaries and divergent boundaries. One major volcanic belt is called the Pacific Ring of Fire. It borders the Pacific Ocean.
Many of the volcanoes along the Ring of Fire form at convergent plate boundaries. These can include ocean/continental such as long the northwest coast of the United States including Mt. St. Helens and Mt. Hood and along the west coast of South America. Japan, the Philippian Islands, and New Zealand form at convergent ocean/ocean convergent plate boundaries. These volcanic islands along plate boundaries are called island arc volcanoes.
Other volcanoes form at divergent plate boundaries. In places such as along the Mid Atlantic Ridge, ocean crust is being pulled apart. Many of the volcanoes along the Mid Atlantic Ridge remain below the surface of the water. Iceland, one of the most volcanic places on earth, is along the Mid Atlantic Ridge. Mt. Kilimanjaro in Africa is at a divergent plate boundary where continental crust is being pulled apart.
Other volcanoes form at Hot Spots, or weak spots in the crust away from plate boundaries where magma rises to the surface. Two examples of hot spots include Hawaii and Yellowstone.
1. What is a volcano?