Exploring the submarine ring of fire: Mariana Arc-Western Pacific

Sampling an erupting volcano at 550-m depth, discovering roiling pools of liquid sulfur at 400-m depth, watching tropical fish swimming amid fields of black smoker vents, and encountering a blizzard of liquid carbon dioxide globules rising from fractured lava flows at 1600-m depth all sound like wishful thinking or scenes from a science fiction movie. But, we had the good fortune to observe these and other previously unseen phenomena between 2004 and 2006 during a series of expeditions to the Mariana arc in the western Pacific. We describe here several of the most interesting sites, along with their geologic and oceanographic contexts.