Island Arcs: Chains of Fire

When an oceanic plate subducts beneath another oceanic plate, the volcanism creates a curved chain of islands called an island arc. Japan, the Philippines, Indonesia, and the Caribbean islands are all products of this process.

Indonesia sits atop the most complex tectonic intersection on Earth, where several plates converge. This has produced over 130 active volcanoes — more than any other country. Its archipelago of over 17,000 islands was built almost entirely by volcanism at subduction zones, making it both geologically spectacular and extraordinarily dangerous.