The Pacific Ring of Fire is the name for a horseshoe-shaped region of high seismic and volcanic activity surrounding the Pacific Ocean Basin. In addition to volcanoes, the area encompasses major fault zones. It spans 25,000 miles and touches a number of island chains, as well as four continents.
Many of the volcanoes and fault zones along the Ring of Fire are well-known. Mt. St. Helens in Washington State for example, is recognized throughout the world for erupting in 1980. It is part of North America's Cascade volcano chain, which is part of the Ring of Fire. Krakatoa and Mount Fuji are other famous Ring of Fire volcanoes.
The high seismic activity of the Ring of Fire is a result of the number of tectonic plate boundaries that compose it. In the eastern portion of the ring, the Coco and Nazca plates continue to subduct under the South American plate. During subduction, one plate is forced beneath another. Generally the plate that is forced under is the heavier of the two. When the tension caused by subduction temporarily eases, an earthquake, such as the one that rocked Japan in 2011, is possible.
Although the people who live along the Ring of Fire face the possibility of earthquakes, tsunamis and volcanic eruptions, they also live in an area where volcanic activity has created rich soil for farming.