What is a Weegy subduction zone

Subduction and subduction zones

Subduction takes place along convergent (colliding) plate boundaries. It describes the immersion of a tectonic plate (oceanic plate, continental plate) into the earth's mantle. There the subducted plate is at least partially melted. Magma is created. Part of the magma rises behind the subduction zone and is erupted on volcanoes. It is always the ocean floor that submerges. This transports a lot of water into the earth's mantle. The water influences chemical reactions and reduces the melting point of rocks. The ocean floor is denser and therefore heavier than the continental mainland. This floats like an iceberg on top.

Subduction zone

The area of ​​the plate boundaries where subduction takes place is called the subduction zone. Depending on the size of the plates involved, subduction zones can be many thousands of kilometers long. They form the deep-sea trenches of the oceans. The deepest point on earth is the Mariana Trench with a depth of a good 11,000 meters. Numerous earthquakes form along subduction zones. Some of the most catastrophic quakes in history occurred here. Examples are the Sumatra earthquake in 2004 and the Tōhoku earthquake in 2011. Both earthquakes triggered devastating tsunamis that killed thousands of people.

One of the most dangerous subduction zones in the world is the Sunda Arc. This is 6000 km long and was created by the subduction of the Indo-Australian plate under the Sunda and Burma plates. The Sumatra earthquake occurred in this subduction zone. It is also responsible for such well-known volcanoes as Toba, Krakatau, Merapi, Bromo, or Rinjani (Samalas) and Tambora.

The Tōhoku earthquake manifested itself at the Japan Rift. There the Pacific plate is subducted under the Philippine plate. One of the consequences is the formation of many volcanoes in the Japanese archipelago behind the subduction zone. Most subduction zone volcanoes form a good 150 km away behind a deep sea trench. In the case of the Japan Trench, there are also small submarine mini-volcanoes in front of the deep-sea trench. These are called petit spots and are only 50 m high.