[Sources consulted: United States Geological Survey,
Active Volcanoes and Plate Tectonics, “Hot Spots” and the “Ring of Fire,” at
http://vulcan.wr.usgs.gov/Glossary/PlateTectonics/Maps/map_plate_tectonics_world.html; and Frank Press, Raymond Siever, John Grotzinger, and Thomas H. Jordan,
Understanding Earth, 4th ed. (New York: W. H. Freeman, 2004), p. 27]