GEOLOGY

Detailed explanation-1: -Magma formed above a subducting plate slowly rise into the overriding crust and finally to the surface forming a volcanic arc, a chain of active volcanoes which parallels the deep ocean trench.

Detailed explanation-2: -Subduction zones produce volcanic arcs, curving chains of steep-sided volcanoes, for example the Aleutian Islands in Alaska. Volcanoes associated with subduction zones generally have steep sides and erupt explosively. Why are the subduction zone volcanoes so steep? The lavas erupted there are rich in silica.

Detailed explanation-3: -Volcanic Island Arcs are formed at the margin of subduction zones. They are formed due to the partial melting of a subducting plate. They are also accompanied by trenches or deep depressions in the ocean. Subduction occurs due to the collision of two tectonic plates.

Detailed explanation-4: -Beneath the ocean, massive tectonic plates converge and grind against one another, which drives one below the other.

Detailed explanation-5: -intraoceanic arcs (primitive arcs) form when oceanic crust subducts beneath other oceanic crust on an adjacent plate, creating a volcanic island arc.