An example of a volcanic island arc is?

• A. The Aleutian Islands in Alaska
• B. The Himalayan range
• C. The Andes
• D. The East African Rift

Answer: (A)

Volcanic island arcs form where an oceanic plate sinks beneath another plate, melting as it descends and feeding magma that builds a curved chain of volcanic islands parallel to a trench. The Aleutian Islands in Alaska sit along the boundary where the Pacific Plate is subducting beneath the North American Plate, creating a curved belt of volcanic islands and a nearby deep trench. The Himalayas come from continental collision and uplift, not subduction of oceanic crust to form an island arc. The Andes are a continental volcanic arc on the edge of a continent, not an island chain. The East African Rift is a continental rift with volcanism from crustal stretching, not an island arc. Hence, the Aleutians are the example of a volcanic island arc.