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: -A subduction zone is also generated when two oceanic plates collide-the older plate is forced under the younger one-and it leads to the formation of chains of volcanic islands known as island arcs. Examples include the Mariana Islands in the western Pacific Ocean and the Aleutian Islands, off the coast of Alaska.

Detailed explanation-3: -When two oceanic plates collide against each other, the older and therefore heavier of the two subducts beneath the other, initiating volcanic activity in a manner similar to that which occurs at an oceanic-continental convergent plate boundary and forming a volcanic island arc.

Detailed explanation-4: -An island volcanic arc forms in an ocean basin via ocean-ocean subduction. The Aleutian Islands off the coast of Alaska and the Lesser Antilles south of Puerto Rico are examples. A continental volcanic arc forms along the margin of a continent where oceanic crust subducts beneath continental crust.

Detailed explanation-5: -Because the surface of Earth is curved, the line of volcanoes forms in an arcuate pattern in much the same manner as an arc is produced when a planar surface intersects a sphere. Island arcs are usually accompanied by rapid erosion and sedimentation into accompanying basins.