Ring of Fire, also called Circum-Pacific Belt or Pacific Ring of Fire, long horseshoe-shaped seismically active belt of earthquake epicentres, volcanoes, and tectonic plate boundaries that fringes the Pacific basin. For much of its 40,000-km (24,900-mile) length, the belt follows chains of island arcs such as Tonga and New Hebrides, the Indonesian archipelago, the Philippines, Japan, the Kuril Islands, and the Aleutians, as well as other arc-shaped geomorphic features, such as the western coast of North America and the Andes Mountains. Volcanoes are associated with the belt throughout its length; for this reason it is called the âRing of Fire.â A series of deep ocean troughs frame the belt on the oceanic side, and continental landmasses lie behind. Most of the worldâs earthquakes, the overwhelming majority of the worldâs strongest earthquakes, and approximately 75 percent of the worldâs volcanoes occur within the Ring of Fire.