Pacific Ring of Fire Expedition. Photosynthetic green and red algae is growing on the same rocks as chemosynthetic bacterial mat near the top of East Diamante volcano. Usually, these two life forms are not found together because one depends on the sun for energy and the other on chemical energy from deepsea hydr othermal vents. Here, however, submarine volcanoes come close to the surface.

Pacific Ring of Fire Expedition. Colorful tropical fish, soft corals, and basket stars cover the top of a volcanic spine that extends into the upper ocean where sunlight can penetrate at East Diamante volcano.

Pacific Ring of Fire Expedition. Colorful tropical fish, soft corals, and basket stars cover the top of a volcanic spine that extends into the upper ocean where sunlight can penetrate at East Diamante volcano.

Pacific Ring of Fire Expedition. Colorful tropical fish, soft corals, and basket stars cover the top of a volcanic spine that extends into the upper ocean where sunlight can penetrate at East Diamante volcano.

Pacific Ring of Fire Expedition. Colorful tropical fish, soft corals, and basket stars cover the top of a volcanic spine that extends into the upper ocean where sunlight can penetrate at East Diamante volcano.

Pacific Ring of Fire Expedition. Fluffy white bacterial mat covers yellow corals and the surrounding rocks near the shallow summit of East Diamante volcano. The corals are dependent on sunlight whereas the mat uses the chemical energy from hydrothermal fluids seeping out of the volcano.

Pacific Ring of Fire Expedition. Tropical fish swim by rocks coated with white bacterial mat . Unlike the fish, the bacterial mat is dependent on the chemical energy provided by seafloor hot springs venting near the top of East Diamante volcano.

Pacific Ring of Fire Expedition. Colorful tropical fish, soft corals, and basket stars cover the top of a volcanic spine that extends into the upper ocean where sunlight can penetrate at East Diamante volcano.

Pacific Ring of Fire Expedition. Three-dimensional view of East Diamante submariane volcano. This active volcano was visited on the Submarine Ring of Fire 2004 expedition. The central peaks dive site is an area where hydrothermal activity overlapped with coral reef communities. The image is vertically exaggerated two times.

Pacific Ring of Fire Expedition. The summit of Diamante volcano, created from an EM300 grid. The bathymetry data were collected on the Submarine Ring of Fire 2002 and 2003 expeditions. The major vent sites visited on dives R787 and R788 are noted.

Pacific Ring of Fire Expedition. The vertical column in the center of the image, called a dike, rises from below sea level to the pinnacle at the top of the ridge. Interlaid massive lavas (darker horizontal bands) and ash-rich lava units (reddish) are also exposed on the islets of Maug.

Pacific Ring of Fire Expedition. While attempting to sample an outcrop of hydrothermally altered lava, the view changed rapidly (over a 2 minute time span ) from good visibility to chunks of rock, sulfur and ash totally obscuring the outcrop from our view . The outcrop is ~ 40 cm high. This view is is midway in the process.

Pacific Ring of Fire Expedition. Thick orange bacterial mat found near the summit of Northwest Eifuku volcano grow where warm hydrothermal vent fluids seep out of the seamount. The orange color reflects the fact that iron is coming out in the vent fluids.

Pacific Ring of Fire Expedition. Thick orange bacterial mat found near the summit of Northwest Eifuku volcano grow where warm hydrothermal vent fluids seep out of the seamount. The orange color reflects the fact that iron is coming out in the vent fluids.

Pacific Ring of Fire Expedition. Thick orange bacterial mat found near the summit of Northwest Eifuku volcano grow where warm hydrothermal vent fluids seep out of the seamount. The orange color reflects the fact that iron is coming out in the vent fluids.

Pacific Ring of Fire Expedition. Bubbles of liquid CO2 float out of the seafloor at Champagne vent on Northwest Eifuku volcano. The hydrothermal vent fluids being emitted by this volcano had large amounts of dissolved gases in them.

Pacific Ring of Fire Expedition. White smoky vent fluid rises out of small sulfur chimneys at Northwest Eifuku volcano. This area was named Champagne vent because bubbles of liquid CO2 were rising out of the seafloor.

Pacific Ring of Fire Expedition. White smoky vent fluid rises out of small sulfur chimneys at Northwest Eifuku volcano. This area was named Champagne vent because bubbles of liquid CO2 were rising out of the seafloor.

Pacific Ring of Fire Expedition. White smoky vent fluid rises out of small sulfur chimneys at Northwest Eifuku volcano. This area was named Champagne vent because bubbles of liquid CO2 were rising out of the seafloor.

Pacific Ring of Fire Expedition. A dense bed of hydrothermal mussels covers the slope of Northwest Eifuku volcano near a seafloor hot spring called Champagne vent . Other vent animals living among the mussels include shrimp, limpets, and Galatheid crabs.

Pacific Ring of Fire Expedition. A dense bed of hydrothermal mussels covers the slope of Northwest Eifuku volcano near a seafloor hot spring called Champagne vent . Other vent animals living among the mussels include shrimp, limpets, and Galatheid crabs.

Pacific Ring of Fire Expedition. A dense bed of hydrothermal mussels covers the slope of Northwest Eifuku volcano near a seafloor hot spring called Champagne vent . Other vent animals living among the mussels include shrimp, limpets, and Galatheid crabs.

Pacific Ring of Fire Expedition. A dense bed of hydrothermal mussels covers the slope of Northwest Eifuku volcano near a seafloor hot spring called Champagne vent . Other vent animals living among the mussels include shrimp, limpets, and Galatheid crabs.

Pacific Ring of Fire Expedition. Map of NW Eifuku Volcano showing location of Champagne Vents near summit of mountain.

Pacific Ring of Fire Expedition. Active "smoker" chimneys precipitating iron, copper and zinc sulfides from 230øC fluid. 9 meters tall from the base to the top of the chimneys seen in the photograph. Dark beehive-type chimneys, here about 30 cm tall, commonly sit on top of these structures.

Pacific Ring of Fire Expedition. Flatfish (sole) were found in great numbers at Kasuga-1 and Daikoku volcanoes. Most of the fish in this image are < 10 cm long (~4 in).

Pacific Ring of Fire Expedition. Global view of the Pacific Ring of Fire.

Pacific Ring of Fire Expedition. Galatheid crabs and shrimp graze on bacterial filaments. The black 'scars' on the mussels are anchor points, left by mussels who have cut their threads and moved.

Pacific Ring of Fire Expedition. A rare sight at hydrothermal systems, this shark (~ 1.5 meters long, 5 ft), surprised us at Kasuga-2.

Pacific Ring of Fire Expedition. Conical limpets (2cm, 0.75 in) cover the rocks surfaces at East Diamante. The white dots on the rocks and shells are limpet egg cases. An arc crab is investigating the scene.

Pacific Ring of Fire Expedition. Large amounts of biomass feeding on white flocculent mats on periphery of white smokers include vent shrimp and mussels showing that microorganisms are channeling energy up the food chain.

Pacific Ring of Fire Expedition. A contact between the lower basaltic and upper felsic ash units in the wall of the West Rota caldera. The outcrop is approximately 2 meters tall.

Pacific Ring of Fire Expedition. Map of Mariana Back Arc Spreading Center volcanoes and recent volcanic activity.

Pacific Ring of Fire Expedition. A geological cross-section of the Mariana Arc showing the Mariana Trench and Back Arc Spreading Center.

Pacific Ring of Fire Expedition. Three-dimensional view of the Maug Caldera (2 X vertical exagerration). Data acquired with an EM300 sonar system and gridded at 10 meter interval. Depth range from 241 to 25 meters (790-82 feet). On this expedition the survey of the Maug central lava dome was completed.

Pacific Ring of Fire Expedition. In places at NW Eifuku, mussels are so dense that they obscure the bottom. [The mussels are ~18 cm (7 in) long. The white galatheid crabs are ~6 cm (2.5 in) long.]

Pacific Ring of Fire Expedition. The vent mussel Bathymodiolus: water is drawn through the siphons at the open end to the left; the foot extends on the right and attaches the mussel to the rock with byssal threads. [The mussels are up to 18 cm (7in) long.]

Pacific Ring of Fire Expedition. Limpets were seen grazing near the seeping fluids. They tend to form small clusters. This animal is probably an undescribed species related to a limpet that occurs on seamounts off Japan. The limpet is > ~0.5 inches (~1.5 cm).

Pacific Ring of Fire Expedition. This plankton net is being deployed to collect near-surface plankton in Maug caldera. The net is about 2 m (6.5 ft) long and has a mesh size of 236 microns (0.25 mm or .01 inch).

Pacific Ring of Fire Expedition. A non-vent species of shrimp keeps an eye on ROPOS at Northwest Rota-1 volcano.

Pacific Ring of Fire Expedition. Shrimp and crabs living near the summit of Northwest Rota-1 volcano graze bacterial mats on the rocks at hydrothermal vents. They also have to watch out for volcanic eruptions at this active submarine volcano.

Pacific Ring of Fire Expedition. NW Rota 1 EM300 bathymetry. The volcano rises to a height of 535 meters below sea level. Its base is over 2000 meters deep. Brimstone Pit is near the summit of the volcano at 555 meters depth.

Pacific Ring of Fire Expedition. This cross-section of NW Rota 1 shows the distribution of particles suspended in the waters around the volcano, as measured by an optical turbidity sensor mounted on a CTD package ("tow-yo" path shown by black saw-tooth line). The thin plumes above the volcano originate from Brimstone Pit at the summit.

Pacific Ring of Fire Expedition. This pinnacle rises to 167 meters below the surface. The coiled up pink masses are basket sea stars (about 50 cm across). A myriad of small fish, probably wrasses, swarm around the top of Pinnacle Cone. Turbulence around the top of the structure attracts all the suspension feeders who feed on plankton.

Pacific Ring of Fire Expedition. Photograph shows a piece of one of the chimney spires in the next image. It has been cut in half and is 22 cm long. The interior of the chimney is lined by a copper-rich mineral, chalcopyrite. The gray and white zone near the exterior of the chimney is composed of iron, zinc and barium-rich minerals called pyrite, sphalerite and barite.

Pacific Ring of Fire Expedition. Left to right: Verena Tunnicliffe, Kim Juniper, Keith Shepherd and Bob Holland are gathered around the ROPOS console, identifying vent species on the seafloor.

Pacific Ring of Fire Expedition. ROPOS deployment from the "fantail" of the THOMPSON.

Pacific Ring of Fire Expedition. ROPOS was covered in sulfur droplets after its close encounter with sulfur, rocks and ash at Brimstone Pit.

Pacific Ring of Fire Expedition. Satellite derived bathymetry of the Mariana Arc region. EM300 multibeam bathymetry is overlaid on the satellite data.

Pacific Ring of Fire Expedition. A hydrothermal vent site near the summit of the volcano. Hot water is percolating out of the rocks and sediments in this area. The light colored objects in the lower right are sulfur rocks.