why is the ring of fire so active

The is a ring of volcanoes around the Pacific Ocean that result from subduction of oceanic plates beneath lighter continental plates. Subduction of oceanic. Most of the Earth's volcanoes are located around the Pacific Ring of Fire because that the location of most of the Earth's subduction zones. A subduction zone is a place where one plate of oceanic lithosphere (= the crust + uppermost
) is shoved under another plate. The downgoing plate is always the oceanic one. All while it was oceanic plate it collected water-saturated sediments and its uppermost few hundred meters got water saturated also. As it is shoved into the hotter mantle the plate heats up and all this water and other volatiles boil off and migrate upwards through the overlying plate. The addition of volatiles such as water to the hot overlying mantle causes partial melting and the production of. This magma rises up through the over-lying plate to erupt at the surface. If the overlying plate is a continent, you get a chain of volcanoes such as the Andes or Cascades. If the overlying plate is ocean you get a chain of volcanic islands such as the Marianas or Aleutians. This is also where the Earth's deep ocean trenches are and where the Earth's deep earthquakes are.

The trenches form because the downgoing plate is bent downward as it subducts. The earthquakes form as the two plates scrape against each other (earthquakes down to about 150 km) and then as the downgoing plate bends (earthquakes down to about 700 km). The earthquakes do a very good job of tracing the position of the downgoing plate. These zones of earthquakes are called Wadati-Benioff zones, after the two seismologists who first recognized them. The Ring of Fire can also be defined by tectonic plates, the moving sections of the Earth's crust. It extends around the edge of the Pacific plate but also includes a few smaller plates. These are the Filipino plate bordering the Philippines and Japan, the Juan de Fuca plate near the U. S. states of California, Oregon, and Washington, the Cocos and Caribbean plates along Mexico and Central America, and the Nazca plate along the Western side of South America. The Ring of Fire has long been an active site for earthquakes and volcanoes because of the active plate boundaries. When tectonic plates move against each other at boundaries, they cause earthquakes and eruptions of magma, which form into volcanoes. The tectonic boundaries of the Ring of Fire are so active because they are mostly subduction zones.

This means that one plate, the heavier of the two, slides under the other plate at the boundary. A subduction zone creates trenches in the ocean and is just right for building mountains, for volcanic eruptions, and for earthquakes. Mountain ranges in the Ring of Fire, produced by subduction of one plate under another include the Andes Mountains of South America, the Cascade Range in the Western U. S. and the Southern Alps in New Zealand. The Ring of Fire has also produced three-quarters of all of the world's volcanoes. These include some of the most famous and destructive volcanoes, like Krakatoa in Indonesia, Mt. Fuji in Japan, and Mount St. Helens in the U. S. The Ring of Fire volcanoes are also some of the most active in the world. In New Zealand, Mount Ruapehu erupts nearly every year. Most are minor eruptions, but other Ring of Fire volcanoes are much more destructive. When Krakatoa erupted in 1883, it destroyed the island on which it was situated and itself. Today, a new volcano and island are in the process of forming. The island is now called Anak Krakatau, which means child of Krakatoa. Many of the volcanoes in the Ring of Fire form inland from the ocean, while others form as volcanic island chains.

The Aleutian Islands of Alaska are an example. Some of the volcanoes form very quickly, such as Paricutun did in Mexico. A single eruption in 1943 created this mountain in the middle of an unsuspecting cornfield. Volcanoes are some of the most spectacular results of subduction in the Ring of Fire, but they are not the only consequences. Most of the world's earthquakes, and many of the largest, occur along the Ring of Fire. Small earthquakes occur regularly and larger events have occurred mostly along the Western coasts of North and South America and in Japan. The Ring of Fire is a zone of intense tectonic activity around the edges of the Pacific Ocean. Most of the world's earthquakes and volcanoes occur here as a result of subduction, the sinking of one tectonic plate under another. The ring is more of a horseshoe shape and traces the Pacific Ocean from New Zealand north through Indonesia, the Philippines, and Japan, along Russia's Pacific coast, over to Alaska and down the Western coasts of North and South America. Famous, active and destructive volcanoes, like Mount Saint Helens, Krakatoa, Mount Fuji, Paricutun and Mount Ruapehu were formed in the Ring of Fire. The Ring of Fire Subduction Volcanoes Earthquakes

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