PMEL Earth-Ocean Interactions Program logo National Oceanic and Atmospheric Administration Pacific Marine Environmental Laboratory Earth-Ocean Interactions Program
Ring of Fire

Submarine Ring of Fire

The “Ring of Fire” is a circular arc of active volcanoes that surrounds the Pacific Ocean basin. Much is known about the volcanoes on land within the Ring of Fire (including the Aleutians, the Cascades, the Andes), but little is known about the submarine volcanoes, simply because they are hidden underwater. The Submarine Ring of Fire program aims to explore this poorly understood realm and catalyze research into the extraordinary diversity of subduction zone hydrothermal vent ecosystems.






Mariana ArcBrimstone eruption

The Mariana Volcanic Arc extends from 13°N to 23°N in the western Pacific Ocean, northwest of Guam. The Mariana region contains 9 volcanic islands and more than 60 submarine volcanoes, of which at least 20 are hydrothermally active. Discoveries have included actively erupting volcanoes, sites emitting liquid CO2, and craters filled with bubbling molten sulfur, all with an extraordinary diversity of chemosynthetic biological communities. These discoveries inspired the establishment of the Mariana Trench Marine National Monument.

Expeditions: 2010 | 2009 | 2006 | 2004 | 2003


More information is available on the EOI Mariana Arc page.

Fiery blastNE Lau Basin

The Lau Basin is home to the Earth's highest subduction rates and fastest-opening backarc basin, which results in one of the Earth’s most densely populated areas of submarine volcanism and hydrothermal activity. Exploratory expeditions in 2008-2011 discovered and mapped numerous sites of hydrothermal activity and discovered the deepest active eruption site ever witnessed.

Expeditions: 2012 | 2010 | 2009 | 2008


More information is available on the EOI Lau Basin page.

map of BrothersKermadec Arc

The Kermadec Arc is an active volcanic island arc stretching north-northeast from New Zealand's North Island towards Tonga. While only a few volcanoes in the arc are tall enough to form islands, it also includes about 30 submarine volcanoes. The EOI program has explored many of the submarine volcanoes of the Kermadec Arc with New Zealand and other international colleagues.

Expeditions: 2007 | 2005


More information is available on the EOI Kermadec Arc page.

Chimney and marker in Magic  Mountain areExplorer Ridge

Explorer Ridge lies at the northern end of a chain of 3 spreading centers located off the west coast of North America in the NE Pacific. Explorer Ridge consists of one major segment, Southern Explorer Ridge, and several smaller segments. Magic Mountain is a large active hydrothermal vent area located on the Southern Explorer Ridge. Before 2002, Explorer Ridge was the least explored of the NE Pacific spreading centers, even though it was known to have robust hydrothermal activity and is seismically active. The 2002 mapped the Magic Mountain vent site in unprecedented detail.

Expeditions: 2002


More information is available on the EOI Explorer Ridge page.