A hydrothermal vent structure, with black smoke emanating as part of a focused plume of hot hydrothermal fluid. An instrument has been placed at the base of the venting source to monitor characteristics of the hot fluid. The cylinders in the lower left portion of this image are titanium bottles (Major Samplers) that are used to bring samples of hydrothermal fluids to the surface for laboratory analyses. The platform to which the fluid samplers are attached is the sample basket on the Deep Submergence Vehicle (DSV) Alvin.

An animal community with tube worms (Riftia pachyptila) thriving on the seafloor with the Axial Summit Trough (AST) of the East Pacific Rise (EPR). Shimmering water shown in this image is the result of warm water escaping from the seafloor. In the foreground of this image is the base of an instrument that is used to monitor water characteristics.
Species (common):
Year: 2004
Details:
Media Type: Photograph
Data Type: Photograph
Device Type: Camera:Digital
Feature: EPR:9N:Tica
Investigator: Vicki Ferrini
Expedition: AT11-20
Chief Scientist: Marvin Lilley

Hot hydrothermal fluids are frequently observed emanating from small orifices on the tops and sides of hydrothermal vent structures. The hot fluids are highly localized, and ambient seafloor temperatures (~2 degrees Celsius) are common within a few centimeters of active orifices.
Species (common):
Year: 2004
Details:
Media Type: Photograph
Data Type: Photograph
Device Type: Camera:Digital
Feature: EPR:9N:Tica
Investigator: Vicki Ferrini
Expedition: AT11-20
Chief Scientist: Marvin Lilley
Species: Riftia pachyptila (Tube worm) Bathymodiolus thermophilus

The base of a hydrothermal vent structure located within an area of diffuse flow. Consistent focused flow of hot hydrothermal fluids can result in the formation of hydrothermal vent structures that are formed as metal rich fluids result in hydrothermal deposits rich in minerals like sulfur, copper, zinc, gold, and iron. Hydrothermal structures can grow to be several meters in height and width.
Species (common):
Year: 2004
Details:
Media Type: Photograph
Data Type: Photograph
Device Type: Camera:Digital
Feature: EPR:9N:Tica
Investigator: Vicki Ferrini
Expedition: AT11-20

At mid-ocean ridges like the East Pacific Rise (EPR), collapse features are common along the axis of the spreading center. Cracks and collapse features can help with the mixing of cool seawater with hot hydrothermal fluids, and also provide pathways for warm water to escape from the seafloor resulting in conditions optimal for specialized organisms like these.
Species (common):
Year: 2004
Details:
Media Type: Photograph
Data Type: Photograph
Device Type: Camera:Digital
Feature: EPR:9N:Tica
Investigator: Vicki Ferrini
Expedition: AT11-20
Chief Scientist: Marvin Lilley

Animal communities like these, thrive in extreme environements in the deep sea. They are subjected to extreme pressure (at over 2 km water depth) and are exposed to high temperatures and chemical compounds that are toxic to most other organisms.
Species (common):
Year: 2004
Details:
Media Type: Photograph
Data Type: Photograph
Device Type: Camera:Digital
Feature: EPR:9N:Tica
Investigator: Vicki Ferrini
Expedition: AT11-20
Chief Scientist: Marvin Lilley
Species: Riftia pachyptila (Tube worm) Bathymodiolus thermophilus Munidopsis subsquamosa

Localized patches of organisms like these tubeworms (Riftia pachyptila) and mussels (Bathymodiolus thermophilus) are clustered around localized areas of warm water released from the seafloor. These sorts of diverse biological communities are chemosynthetic, deriving energy from chemicals dissolved in the warm hydrothermal fluids.
Species (common):
Year: 2004
Details:
Media Type: Photograph
Data Type: Photograph
Device Type: Camera:Digital
Feature: EPR:9N:Tica
Investigator: Vicki Ferrini
Expedition: AT11-20
Chief Scientist: Marvin Lilley

Animals like these are distributed on the seafloor within the Axial Summit Trough (AST) of the East Pacific Rise where warm water is released from the seafloor. The warm water is the result of hot fluids deep beneath the seafloor mixing with cooler sea water near the seafloor surface. This kind of warm water flow, is not focused but is distributed over variable spatial scales and is referred to as diffuse flow.
Species (common):
Year: 2004
Details:
Media Type: Photograph
Data Type: Photograph
Device Type: Camera:Digital
Feature: EPR:9N:Tica
Investigator: Vicki Ferrini

Wall of the Axial Summit Trough (AST) of the East Pacific Rise. The layers shown here are due to the emplacement of lava during repeat eruptions at this site. The fractured wall is due to collapse along the AST as lava recedes into the eruptive fissure of the AST.
Species (common):
Year: 2004
Details:
Media Type: Photograph
Data Type: Photograph
Device Type: Camera:Digital
Feature: EPR:9N
Investigator: Vicki Ferrini
Expedition: AT11-20
Chief Scientist: Marvin Lilley
Species: Munidopsis subsquamosa

Dense, white bacterial mats colonize oxidized hydrothermal sediment and small, extinct sulfide chimneys to the west of Cuchalainn. This image was first published in a Ph.D. Dissertation by M. Schrenk, 2005.
Species (common):
Year: 2003
Details:
Media Type: Photograph
Data Type: Photograph
Device Type: Camera:Digital
Feature: JdF:Endeavour:Mothra:Cuchalainn
Investigator: Deborah Glickson
Expedition:
Chief Scientist:
Species: