A weekly feature provided by scientists at the Hawaiian Volcano Observatory. Hot-spot island chains include the Hawaiian, Marquesas, Society, Pitcairn, Samoan, and Galapagos archipelagos.
Volcanoes are also common around the edge of the Pacific Ocean.
The Pacific rim volcanoes are related to plate boundary processes. The surface of the Earth is made up of about 14 rigid plates, which move relative to each other like boards floating on a pond. Where two plates collide, one plate usually sinks beneath the other deep into the mantle of the Earth. The sinking plate melts to form magma, which rises and forms volcanoes on the overriding plate. This process forms the ring of volcanoes around most of the Pacific Ocean.