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Last updated on April 18, 2014 at 11:09 EDT

Pacific Ring of Fire

The Pacific Ring of Fire, or Ring of Fire for short, is an area where a large number of earthquakes and volcanic eruptions occur in the basin of the Pacific Ocean. In a 25,000 mile horseshoe shape, it’s associated with an almost continuous series of oceanic trenches, volcanic belts, volcanic arcs and/or plate movement. The Ring of Fire contains 452 volcanoes and is home to over 75 percent of the world’s active and dormant volcanoes. It’s sometimes called the circum-Pacific belt or the circum-Pacific seismic belt.

Approximately 90 percent of the world’s earthquakes and 81 percent of the world’s largest earthquakes happen along the Ring of Fire.

This region is a direct result of plate tectonics and the movement and collisions of lithospheric plates. The eastern part of the ring is the result of the Nazca Plate and the Cocos Plate being subducted underneath the westward moving South American Plate. The Cocos Plate is being subducted underneath the Caribbean Plate, located in Central America. A part of the Pacific Plate in addition to the small Juan de Fuca Plate are being subducted beneath the North American Plate. Along the northern part, the northwestward-moving Pacific plate is being subducted underneath the Aleutian Islands arc. Farther westwards, the Pacific plate is being subducted along the Kamchatka Peninsula arcs on south past Japan. The southern part is more complicated, with numerous smaller tectonic plates in collision with the Pacific plate from the Mariana Islands, the Philippines, Tonga, Bougainville, and New Zealand; this piece excludes Australia, due to the position of which being in the center of its tectonic plate. Indonesia lies between the Ring of Fire along the northeastern islands that are adjacent to and including New Guinea and the Alpide belt along the south and west from Sumatra, Bali, Java, Flores, and Timor. The famous, and very active, San Andreas Fault zone of California is a transform fault which offsets a piece of the East Pacific Rise under southwestern United States and Mexico. The movement of the fault creates a number of small earthquakes, at multiple times a day, the majority of which are too small to be felt. The active Queen Charlotte Fault on the western coast of the Haida Gwaii, British Columbia, and Canada, has created three large earthquakes during the 20th century.

Image Caption: SVG version of Pacific Ring of Fire. Credit: Gringer/Wikipedia

Pacific Ring of Fire