Mountains in the Sea Expedition. Field of yellow Enallopsammia stony coral and pink Candidella, with various sponges, whip coral, and brittle stars.

Mountains in the Sea Expedition. Basalt ridge with crinoids, corals, and sponges.

Mountains in the Sea Expedition. Basalt rocks covered in corals (live and dead), crinoids, sponges, and brittle stars.

Mountains in the Sea Expedition. Forest of bamboo whip corals standing 10-12 feet in height.

Mountains in the Sea Expedition. Basalt ridge with various sponges and corals.

Mountains in the Sea Expedition. Beautiful bouquet of Lophelia, Candidella, and solitary cup corals with brittle stars, crinoids, and various sponges.

Mountains in the Sea Expedition. Bright yellow sponge with whip-like bamboo corals and aggregation of Lophelia, Enallopsammia, and various other sponges and corals.

Mountains in the Sea Expedition. Stunning yellow Enallopsammia stony coral with pink Candidella teeming with brittle stars.

Mountains in the Sea Expedition. Lovely spiraling Iridigorgia coral with brightly colored (apparent) commensal shrimp.

Mountains in the Sea Expedition. Bouquet of Corallium with deep purple Trachythela octocoral, brittle

Mountains in the Sea Expedition. Phenomenal line-up of organisms representing the great diversity on Balanus Seamount - a strange spoon worm, an elegant sea pen, a stalked crinoid, and two xenophyophores (large one-celled organisms) with brittle stars.

Mountains in the Sea Expedition. IFE Hercules ROV collecting corals in a 'forest' of bamboo whip corals on Balanus Seamount.

Mountains in the Sea Expedition. Beautiful white sponge with purple crinoids on Retriever Seamount.

Pacific Ring of Fire Expedition. East Diamante Volcano showing Black Forest vent field.

Pacific Ring of Fire Expedition. Modis satellite image showing eruption at Anatahan Island in May 2003.

Pacific Ring of Fire Expedition. Purple anemone (~6 inches across ~15 cm) on a pumice rock along the east crater wall, West Rota volcano. Anemones are suspension feeders , capturing zooplankton with their tentacles.

Pacific Ring of Fire Expedition. Stunning image of Aquarium site. A picturesque gully with abundant life including algae (red and green), soft corals (pink with white stalks) and tropical fish abound.

Pacific Ring of Fire Expedition. Interlayered basaltic (dark) and felsic (light) ash layers in the east wall of West Rota caldera. This cliff is approximately 3 meters [9 ft.] tall.

Pacific Ring of Fire Expedition. At East Diamante volcano (190 m water depth), chemosynthetic and photosynthetic communities overlap. Patches of encrusting red and green algae lie beneath filamentous bacterial mats on rock surfaces. The small white corals on the rocks are about 5 cm (2 in) long.

Pacific Ring of Fire Expedition. "Bacteria Balls" forming on the left and and rolling down hill on the right. These microbial mats are similar in composition to those as seen at the Yellow Top Vent site. The balls range from 1 to 5 cm (~1 in) in diameter.

Pacific Ring of Fire Expedition. At East Diamante volcano (195 m water depth), tropical fish swim above boulders covered with bacterial mat, which indicates the presence of hydrothermal venting. These fish live in the reef community above and are about 15 cm long (6 in).

Pacific Ring of Fire Expedition. Close-up of a vent barnacle that we're currently trying to identify. The furry things are their little legs (cirri) that capture food particles. The density of barnacles was so extreme here that there was little room for other organisms. The red dots at the top of the image are lasers, spaced 10 centimeters apart for scale.

Pacific Ring of Fire Expedition. The steep slope of the East Diamante volcano is seen in this image from the upper left to the lower right-hand side. Large bl ocks of lava, denoted by the cracks, are covered by a thin layer of sediment. In the foreground, going upslope, are numerous dark (inactive) chimneys protruding out of the jumble of rocks. The one in the foreground is about 5m high.

Pacific Ring of Fire Expedition. Views of the plume coming out of Brimstone Pit crater near the summit of Northwest Rota-1 volcano. The crater rim is visible in the foreground in images #4 and #5. Burst of rocks and droplets of molten sulfur were intermittently erupted from this crater while the remotely operated vehicle ROPOS was on the edge of the crater.

Pacific Ring of Fire Expedition. Views of the plume coming out of Brimstone Pit crater near the summit of Northwest Rota-1 volcano. The crater rim is visible in the foreground in images #4 and #5. Burst of rocks and droplets of molten sulfur were intermittently erupted from this crater while the remotely operated vehicle ROPOS was on the edge of the crater.

Pacific Ring of Fire Expedition. Views of the plume coming out of Brimstone Pit crater near the summit of Northwest Rota-1 volcano. The crater rim is visible in the foreground in images #4 and #5. Burst of rocks and droplets of molten sulfur were intermittently erupted from this crater while the remotely operated vehicle ROPOS was on the edge of the crater.

Pacific Ring of Fire Expedition. Views of the plume coming out of Brimstone Pit crater near the summit of Northwest Rota-1 volcano. The crater rim is visible in the foreground in images #4 and #5. Burst of rocks and droplets of molten sulfur were intermittently erupted from this crater while the remotely operated vehicle ROPOS was on the edge of the crater.

Pacific Ring of Fire Expedition. Views of the plume coming out of Brimstone Pit crater near the summit of Northwest Rota-1 volcano. The crater rim is visible in the foreground in images #4 and #5. Burst of rocks and droplets of molten sulfur were intermittently erupted from this crater while the remotely operated vehicle ROPOS was on the edge of the crater.

Pacific Ring of Fire Expedition. Vertical profile of Brimstone Pit crater, near the summit of NW Rota-1 submarine volcano. Huge billows of yellow-tinged smoke poured from the crater, as well as sulfur, ash and small rocks.

Pacific Ring of Fire Expedition. ROPOS capturing bubbles from the seafloor at Champagne vent site. The plastic tube is 45 cm (18 in) long.

Pacific Ring of Fire Expedition. Close-up of bubbles at the Champagne vent site.

Pacific Ring of Fire Expedition.

Pacific Ring of Fire Expedition. Sampling hydrothermal vent fluids at Cave vent, using the Hot Fluid Sampler (HFS). The white coating on the rocks is bacterial mat. The sampling nozzel is 25 cm (10 in).

Pacific Ring of Fire Expedition. White flocculent mats in and around the extremely gassy high temperature (>100øC) white smokers at the Champagne Vent Site.

Pacific Ring of Fire Expedition. Chemosynthetic microbial mats cover red algae and coral (which are photosynthetic). Hydrothermal vent and coral reef communities are overlapping here at 190 meters, something none of the scientists on the Submarine Ring of Fire Expedition have witnessed before.

Pacific Ring of Fire Expedition. White chimneys at Champagne vent site, NW Eifuku volcano. The chimneys are ~20 cm (8 in) across and ~50 cm (20 in) high, venting fluids at 103§C (217§F). Notice the bubbles in the upper left side of the image.

Pacific Ring of Fire Expedition. The experiment to observe the change in phase of the bubbles collected at Champagne vent site. What began as just solid carbon dioxide hydrate (clathrate) and water on the seafloor , at this depth (300 m) is converting to gaseous carbon dioxide and liquid water - due to the decrease in pressure as the submersible ascends.

Pacific Ring of Fire Expedition. A comparision of Crater Lake and West Rota calderas. Note the similar sized calderas of these volcanoes (same scale for both images). The Crater Lake imagery is a digital elevation model. The West Rota caldera imagery is a bathymetric grid.

Pacific Ring of Fire Expedition. On the summit of East Diamante (170 m water depth), all signs of hydrothermal venting have disappeared. Soft corals (~10-15 cm tall) and tropical fish share the paradise we named "Aquarium".

Pacific Ring of Fire Expedition. The top of one of the central domes in Maug caldera, covered with several different types of corals, sponges (white encrusting towers), algaes. Notice the beautiful lilac anemone near the top (nearly 30 cm, 12 in) hiding 2 clown fish.

Pacific Ring of Fire Expedition. Small crabs (~10 cm) are actively roaming the venting area. This species was first discovered on a seamount at the north end of the Mariana Arc by Japanese biologists. Its name is Austinograea yunohana; yunohana, meaning "flower of sulphur" (upper right inset).The vent shrimp (~3 cm) are probably feeding on bacterial mat coating the rocks (lower right inset).

Pacific Ring of Fire Expedition. Giant smoky plume discovered pouring out of crater near the summit of NW Rota 1 volcano. The crater rim is in the foreground.

Pacific Ring of Fire Expedition. Stalked crinoid (~ 5 inches across, ~13 cm) on the caldera seafloor at West Rota volcano. Crinoids are suspension feeders, using their crown, which is covered with sticky pinnules, to capture zooplankton.

Pacific Ring of Fire Expedition. Columnar jointing in pumice boulder on the top of West Rota volcano. Note crinoid growing on the surface. The image is approximately 0.5 meters [18 in] high.

Pacific Ring of Fire Expedition. Geoff Lebon (foreground) and Ed Baker (background) are removing plume water from the CTD bottles after a tow-yo.

Pacific Ring of Fire Expedition. Cloudy hydrothermal vent fluid seeps out of the summit of Daikoku volcano, typical of the style of venting at many of the Mariana submarine volcanoes.

Pacific Ring of Fire Expedition. Cloudy hydrothermal vent fluid seeps out of the summit of Daikoku volcano, typical of the style of venting at many of the Mariana submarine volcanoes.

Pacific Ring of Fire Expedition. A close up view of tubeworms at a seafloor hot spring on Daikoku volcano. These animals only live at hydrothermal vents.

Pacific Ring of Fire Expedition. Three-dimensional view of Daikoku Volcano. This active volcano was visited on the Submarine Ring of Fire 2004 expedition. The image is vertically exaggerated two times.