What is island arcs?

Question

What is island arcs?

Answer 1

Volcanic arc are islands that are formed on destructive boundaries. This is when two oceanic plates collide and the plate most dense is forced below the other or it is when an oceanic plate collides with a crustal plate, in which, this case the oceanic crust is always forced below the continental as it is more dense. The point where the denser plate is forced below the other is known as the subduction zone. In this zone, there is immense pressure and high temperatures, causing the crust to melt. This molten rock is dense and therefore able to float up to the surface were it cools, constant accumulation of this molten rock will eventually lead to the formation of the island arcs. They are also arc shaped, hence the name island arc. Such islands are the Mariana Islands in the Philippines and Japan.

Answer 2

Island arcs can be created as a piece of oceanic crust moves over a weak spot where volcanic activity is generally assocaited. The continued movement as well as volcanic activity produces a series of volcanoes that line up in an arc as the crust moves over the hot spot. Hawaii is an excellent example of a volcanic island arc.

Answer 3

A volcanic arc (island arcs) is a chain of volcanic islands or mountains formed by plate tectonics as an oceanic tectonic plate subducts under another tectonic plate and produces magma. There are two types of volcanic arcs: oceanic arcs (commonly called island arcs, a type of archipelago) and continental arcs. In the former, oceanic crust subducts beneath other oceanic crust on an adjacent plate, while in the latter case the oceanic crust subducts beneath continental crust. In some situations, a single subduction zone may show both aspects along its length, as part of a plate subducts beneath a continent and part beneath adjacent oceanic crust.

Two classic examples of oceanic island arcs are the Mariana Islands in the western Pacific Ocean and the Lesser Antilles in the western Atlantic Ocean. The Cascade Volcanic Arc in western North America and the Andes along the western edge of South America are examples of continental volcanic arcs. The best examples of volcanic arcs with both sets of characteristics are in the North Pacific, with the Aleutian Arc consisting of the Aleutian Islands and their extension the Aleutian Range on the Alaska Peninsula, and the Kuril-Kamchatka Arc comprising the Kuril Islands and southern Kamchatka Peninsula.

Answer 4

It is a group of islands in a curve.  If the curve is tight, then they may be coral islands that built on the rim of an under water volcano.   Some island arcs are from the crust passing over a hot spot and volcanoes forming islands one after the other - see the Hawaiian Islands.