GEOLOGY

Detailed explanation-1: -Island arcs are long chains of active volcanoes with intense seismic activity found along convergent tectonic plate boundaries. Most island arcs originate on oceanic crust and have resulted from the descent of the lithosphere into the mantle along the subduction zone .

Detailed explanation-2: -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-3: -island arc, long, curved chain of oceanic islands associated with intense volcanic and seismic activity and orogenic (mountain-building) processes. Prime examples of this form of geologic feature include the Aleutian-Alaska Arc and the Kuril-Kamchatka Arc.

Detailed explanation-4: -Oceanic-Oceanic Convergent Boundary At a convergent boundary between two plates of oceanic lithosphere, the older, denser oceanic plate will always subduct, which will cause earthquakes and form volcanic isles.

Detailed explanation-5: -Japan, Indonesia, the Philippine Islands, and the Aleutian Islands of Alaska are examples of island arcs (Figure below). A convergent plate boundary subduction zone between two plates of oceanic lithosphere. Melting of the subducting plate causes volcanic activity and earthquakes.