A spider crab and 1500 m water depth walks across a glassy, jumbled sheet flow in the International District vent field. Credit: UW/NSF-OOI/WHOI; V19.

The large pink octopus (likely Muusoctopus sp.) sits on a ledge at Escargot hydrothermal vent in the International District Hydrothermal Field. Credit: UW/NSF-OOI/CSSF; ROPOS Dive R1719; V14.

This large jelly is called a Fried Egg Jelly (Phacellophora cantschatica).  It normally is a pelagic organism, however this one is on the seafloor, making it vulnerable to spider crab feasting. Photo credit: NSF-OOI/UW/CSSF; Dive R1619; V13

A fossilized lava pond reflects past circulation of melt on the seafloor in a small lava lake. The surface is glass, and fine sediments highight the whirl. VISIONS '13, Leg 4 Photo credit: NSF-OOI/UW/CSSF

"Bathtub" rings mark the egress of lava in collapsed lava lake from the 2011 eruption in Axial Caldera. Credit: UW/NSF-OOI/WHOI; V17.

A basaltic pillar stands in a collapsed lava lake from the 2011 eruption in Axial Caldera. "Bathtub rings mark the egress of lava. Credit: UW/NSF-OOI/WHOI; V17.

Arches capped by glassy basalts remain in a collapsed lava lake at the summit of Axial seamount. Credit: UW/NSF-OOI/WHOI; V17.

An odd basalt formation at the edge of a small, collapsed and frozen lava lake is colonized by tubeworms. Credit: UW/NSF-OOI/WHOI; V17.

An underwater cave filled with rubble from a collapsed lava lake is capped by glassy flows. Credit: UW/NSF-OOI/WHOI; V17.

Cross sectional view of lobate flows and sheet flows on the western wall of Axial Seamouint hosting sea anemones and starfish. Credit: UW/NSF-OOI/ROPOS; V22.

Beautiful pillow basalts with classic bread crust outer surfaces on Axial Seamount. Credit: UW/NSF-OOI/CSSF; V14.

Rat tail fish explore lobate and jumbled lava flows atop Axial Seamount. Credit: UW/NSF-OOI/CSSF; V14.

Pillow basalts and sedimented lobate flows at the summit of Axial Seamount. Credit: UW/NSF-OOI/CSSF; V14.

Frozen fluid lava exits the toe of a pillow basalt on the north face of the >400 ft thick lava flow formed during the 2015 eruption of Axial Seamount. Credit: UW/NSF-OOI/CSSF; V15.

Lightly sedimented pillow flows hosting brittle stars and a coral on Axial Seamount. Credit: UW/NSF-OOI/CSSF; ROPOS Dive R1473; V11.

Beautiful red plumes top the ends of tube worms that are associated with scale worms, limpets and sulfide worms on the Inferno chimney in the ASHES Hydrothermal Field. Credit: D. Kelley, University of Washington, Bureau of Ocean Energy Management, WHOI; V21.

Tube worms thrive on the side of the active >270°C vent called Inferno in the ASHES vent field. Credit: UW/OOI-NSF/WHOI; V19.

The top of Inferno hosts numerous actively venting spires that change yearly. Credit: UW/NSF-OOI/WHOI: V20

Organisms colonize the outer walls of the 16 m-tall hydrothermal edifice called El Guapo. The community structure changes with height above seafloor. Here, limpets, red scale worms and blue protists (ciliates) colonize the outer sulfide walls of the structure. Credit: UW/NSF-OOI/WHOI, V18.

A map of seafloor magnetics highlights the mid-ocean ridge spreading center network that forms the longest mountain chain on Earth. Credit: Center for Environmental Visualization, UW.

Convection cells beneath mid-ocean ridges (divergent plate boundaries) are sites where melt rises up from the mantle. At convergent plate boundaries the oceanic crust and sediments are subducted beneath the bounding plate. Credit: Center for Environmental Visualization, UW.

During subduction of the Juan de Fuca (JdF) Plate beneath the North American Plate, ocean crust and overlying sediments being carried downward heat up, releasing water and other gases into the overlying plate, causing melts to form ~ 50 miles beneath the volcano. Images of the volcanoes are in the USGS public domain. In conrast, Axial Seamount is formed by melts rising from beneath the JdF spreading center that forms the plate boundary between the Pacific Plate and the JdF Plate. Credit. D. Kelley, University of Washington.

A basic bathymetric map centered on the Juan de Fuca Plate. Credit: Credit: Center for Environmental Visualization, UW.

Bathymetric map showing the tectonic plates from California north to Vancover Island. Credit: Center for Environmental Visualization and D. Kelley, University of Washington.

Tectonic plates off Vancouver Island south to California. Credit: Center for Environmental Visualization and D. Kelley, University of Washington.

Transform faults and fracture zones bounding tectonic plates off Vancouver Island south to California. Credit: Center for Environmental Visualization and D. Kelley, University of Washington.

The intermediate spreading Juan de Fuca Ridge hosts multiple segments. A hot spot underlies the ridge beneath Axial Seamount. The Cobb-Eickeberg Seamount chain marks the migration of the Pacific Plate over time. Transform faults and fracture zones bounding tectonic plates off Vancouver Island south to California. Credit: Center for Environmental Visualization and D. Kelley, University of Washington.

Axial Seamount rises to a depth of ~ 1500 m beneath the oceans surface and is cut by the Juan de Fuca Ridge. Transform faults and fracture zones bounding tectonic plates off Vancouver Island south to California. Credit: Center for Environmental Visualization and D. Kelley, University of Washington.

Cobb Seamount is ~ 100 km west of the Cobb hot spot, currently feeding Axial Seamount on the Juan de Fuca Ridge. It is ~ 3.3 Ma in age. The flat-topped summit is at a depth of 200-300 m. It was formed when the summit was above sea level. The inset of Cobb is after Chaytor et al., Seamount morphology in the Bowie and Cobb hot spot trails, Gulf of Alaska. Geochem. Geophys. Geosyst., doi:10.1029/2007GC001712. Credit. D.S. Kelley, University of Washington.

This bathymetric map shows the location of the 2011 and 2015 lava flows in the caldera of Axial Seamount and along the northern rift and the hydrothermal fields (e.g. International District) and diffuse flow sites and other vents. Credit: M. Elend, University of Washington. The bathymetry is courtesy of D. Caress, Monterey Bay Aquarium Research Institute.

Environments at Axial Seamount

The RCA hosts an array of seismometers associated with Axial Seamount and the Cascadia Margin. Credit: University of Washington.

The 2015 eruption of Axial Seamount along the northern rift culminated in a 127 m thick lava flow. Three months after the eruption, during the Regional Cabled Array VISIONS'15 cruise, the remotely operated vehicle ROPOS captured the first images of the flow, landing 10 m away from its base. The summit was covered in acres of microbial mats. Credit. D. Kelley, University of Washington, UW/NSF-OOI/CSSF

This animation shows the relationship between earthquakes and the location of volcanoes around the "ring of fire". Credit: UW Center for Environmental Visualization.

Topographic map of Earth, modified from NOAA (Amante et al., 2009) showing features of the seafloor. Credit: D. Kelley, University of Washington.

The broadband seismometer (left) and low frequency hydrophone (right) are installed on the floor of Axial Seamount at the Central Caldera Site. The 7-function manipulator of ROPOS is connecting the extension cable to the medium powered junction box. The white bags inssulate the broadband from acoustic "noise" associated with curents flowing over the instrument.

The broadband seismometer and hydrophone being installed at the Central Caldera site on Axial Seamount. Credit: UW/NSF-OOI/CSSF; V14

This short-period seismometer was deployed on a flat sheet flow ~ 1.3 km east of the ASHES hydrothermal field in 2013. The black ball in the yellow circle shows that it is perfectly level, helping to insure that the highest quality data comes off of this network. Axial Volcano is likely to be quite seismically active and we are anxious to get the real-time data on shore next year. This will help us understand magma and fluid migration in the subsurface of the volcano...and eventually these data may help us predict an eruption. Several earthquakes were detected in real-time during testing of these seismometers in 2013. Credit: UW/NSF-OOI/CSSF, ROPOS Dive R1635; V13.

Ash (glass shards) rest atop a leveling component on the bottom pressure tilt instrument at the Central Caldera site. Credit: UW/NSF-OOI/CSSF. V15

Beautiful blue ciliates, and white and yellow bacterial mats in the Tiny Towers vent site are imaged live by the ROV Jason. Credit: D. Kelley, University of Washington; V19.