Hydrothermal vent

Hydrothermal vents are fissures on the seabed from which geothermally heated water discharges. They are commonly found near volcanically active places, areas where tectonic plates are moving apart at mid-ocean ridges, ocean basins, and hotspots. ^[1] The dispersal of hydrothermal fluids throughout the global ocean at active vent sites creates hydrothermal plumes. Hydrothermal deposits are rocks and mineral ore deposits formed by the action of hydrothermal vents.

Contents

• Physical properties
• Black smokers and white smokers
• Black smokers 2
• White smokers 2
• Hydrothermal plumes
• Identification and dating
• Ocean biogeochemistry
• Biology of hydrothermal vents
• Biological communities
• Animal-bacterial symbiosis
• Theory of hydrothermal origin of life
• The Deep Hot Biosphere
• Discovery and exploration
• Distribution
• Exploitation
• Conservation
• Geochronological dating
• See also
• References
• Further reading
• External links

Hydrothermal vents exist because the Earth is both geologically active and has large amounts of water on its surface and within its crust. Under the sea, they may form features called black smokers or white smokers, which deliver a wide range of elements to the world's oceans, thus contributing to global marine biogeochemistry. Relative to the majority of the deep sea, the areas around hydrothermal vents are biologically more productive, often hosting complex communities fueled by the chemicals dissolved in the vent fluids. Chemosynthetic bacteria and archaea found around hydrothermal vents form the base of the food chain, supporting diverse organisms including giant tube worms, clams, limpets, and shrimp. Active hydrothermal vents are thought to exist on Jupiter's moon Europa and Saturn's moon Enceladus, ^{[2] [3]} and it is speculated that ancient hydrothermal vents once existed on Mars. ^{[1] [4]}

Hydrothermal vents have been hypothesized to have been a significant factor to starting abiogenesis and the survival of primitive life. The conditions of these vents have been shown to support the synthesis of molecules important to life. Some evidence suggests that certain vents such as alkaline hydrothermal vents or those containing supercritical CO₂ are more conducive to the formation of these organic molecules. However, the origin of life is a widely debated topic, and there are many conflicting viewpoints.

Physical properties

Hydrothermal vents in the deep ocean typically form along the mid-ocean ridges, such as the East Pacific Rise and the Mid-Atlantic Ridge. These are locations where two tectonic plates are diverging and new crust is being formed. ^[5]

The water that issues from seafloor hydrothermal vents consists mostly of seawater drawn into the hydrothermal system close to the volcanic edifice through faults and porous sediments or volcanic strata, plus some magmatic water released by the upwelling magma. ^[1] On land, the majority of water circulated within fumarole and geyser systems is meteoric water and ground water that has percolated down into the hydrothermal system from the surface, but also commonly contains some portion of metamorphic water, magmatic water, and sedimentary formational brine released by the magma. The proportion of each varies from location to location.^{[ citation needed ]}

In contrast to the approximately 2 °C (36 °F) ambient water temperature at these depths, water emerges from these vents at temperatures ranging from 60 °C (140 °F) ^[6] up to as high as 464 °C (867 °F). ^{[7] [8]} Due to the high hydrostatic pressure at these depths, water may exist in either its liquid form or as a supercritical fluid at such temperatures. ^[5] The critical point of (pure) water is 375 °C (707 °F) at a pressure of 218  atmospheres.

However, introducing salinity into the fluid raises the critical point to higher temperatures and pressures. The critical point of seawater (3.2 wt. % NaCl) is 407 °C (765 °F) and 298.5 bars, ^[9] corresponding to a depth of ~2,960 m (9,710 ft) below sea level. Accordingly, if a hydrothermal fluid with a salinity of 3.2 wt. % NaCl vents above 407 °C (765 °F) and 298.5 bars, it is supercritical. Furthermore, the salinity of vent fluids have been shown to vary widely due to phase separation in the crust. ^[10] The critical point for lower salinity fluids is at lower temperature and pressure conditions than that for seawater, but higher than that for pure water. For example, a vent fluid with a 2.24 wt. % NaCl salinity has the critical point at 400 °C (752 °F) and 280.5 bars. Thus, water emerging from the hottest parts of some hydrothermal vents can be a supercritical fluid, possessing physical properties between those of a gas and those of a liquid. ^{[7] [8]}

Examples of supercritical venting are found at several sites. Sister Peak (Comfortless Cove Hydrothermal Field, 4°48′S12°22′W / 4.800°S 12.367°W / -4.800; -12.367 , depth 2,996 m or 9,829 ft) vents low salinity phase-separated, vapor-type fluids. Sustained venting was not found to be supercritical but a brief injection of 464 °C (867 °F) was well above supercritical conditions. A nearby site, Turtle Pits, was found to vent low salinity fluid at 407 °C (765 °F), which is above the critical point of the fluid at that salinity. A vent site in the Cayman Trough named Beebe, which is the world's deepest known hydrothermal site at ~5,000 m (16,000 ft) below sea level, has shown sustained supercritical venting at 401 °C (754 °F) and 2.3 wt% NaCl. ^[11]

Although supercritical conditions have been observed at several sites, it is not yet known what significance, if any, supercritical venting has in terms of hydrothermal circulation, mineral deposit formation, geochemical fluxes or biological activity.^{[ citation needed ]}

The initial stages of a vent chimney begin with the deposition of the mineral anhydrite. Sulfides of copper, iron, and zinc then precipitate in the chimney gaps, making it less porous over the course of time. Vent growths on the order of 30 cm (1 ft) per day have been recorded. ^[12] An April 2007 exploration of the deep-sea vents off the coast of Fiji found those vents to be a significant source of dissolved iron (see iron cycle). ^[13]

Black smokers and white smokers

Some hydrothermal vents form roughly cylindrical chimney structures. These form from minerals that are dissolved in the vent fluid. When the superheated water contacts the near-freezing sea water, the minerals precipitate out to form particles which add to the height of the stacks. Some of these chimney structures can reach heights of 60 m (200 ft). ^[14] An example of such a towering vent was "Godzilla", a structure on the Pacific Ocean deep seafloor near Oregon that rose to 40 m (130 ft) before it fell over in 1996. ^[15]

Black smokers

A black smoker or deep-sea vent is a type of hydrothermal vent found on the seabed, typically in the bathyal zone (with largest frequency in depths from 2,500 to 3,000 m (8,200 to 9,800 ft)), but also in lesser depths as well as deeper in the abyssal zone. ^[1] They appear as black, chimney-like structures that emit a cloud of black material. Black smokers typically emit particles with high levels of sulfur-bearing minerals, or sulfides. Black smokers are formed in fields hundreds of meters wide when superheated water from below Earth's crust comes through the ocean floor (water may attain temperatures above 400 °C (752 °F)). ^[1] This water is rich in dissolved minerals from the crust, most notably sulfides. When it comes in contact with cold ocean water, many minerals precipitate, forming a black, chimney-like structure around each vent. The deposited metal sulfides can become massive sulfide ore deposits in time. Some black smokers on the Azores portion of the Mid-Atlantic Ridge are extremely rich in metal content, such as Rainbow with 24,000  μM concentrations of iron. ^[16]

Black smokers were first discovered in 1979 on the East Pacific Rise by scientists from Scripps Institution of Oceanography during the RISE Project. ^[17] They were observed using the deep submergence vehicle ALVIN from the Woods Hole Oceanographic Institution. Now, black smokers are known to exist in the Atlantic and Pacific Oceans, at an average depth of 2,100 m (6,900 ft). The most northerly black smokers are a cluster of five named Loki's Castle, ^[18] discovered in 2008 by scientists from the University of Bergen at 73°N, on the Mid-Atlantic Ridge between Greenland and Norway. These black smokers are of interest as they are in a more stable area of the Earth's crust, where tectonic forces are less and consequently fields of hydrothermal vents are less common. ^[19] The world's deepest known black smokers are located in the Cayman Trough, 5,000 m (3.1 miles) below the ocean's surface. ^[20]

White smokers

White smoker vents emit lighter-hued minerals, such as those containing barium, calcium and silicon. These vents also tend to have lower-temperature plumes probably because they are generally distant from their heat source. ^[1]

Black and white smokers may coexist in the same hydrothermal field, but they generally represent proximal (close) and distal (distant) vents to the main upflow zone, respectively. However, white smokers correspond mostly to waning stages of such hydrothermal fields, as magmatic heat sources become progressively more distant from the source (due to magma crystallization) and hydrothermal fluids become dominated by seawater instead of magmatic water. Mineralizing fluids from this type of vent are rich in calcium and they form dominantly sulfate-rich (i.e., barite and anhydrite) and carbonate deposits. ^[1]

Hydrothermal plumes

Hydrothermal plumes are fluid entities that manifest where hydrothermal fluids are expelled into the overlying water column at active hydrothermal vent sites. ^[21] As hydrothermal fluids typically harbor physical (e.g., temperature, density) and chemical (e.g., pH, Eh, major ions) properties distinct from seawater, hydrothermal plumes embody physical and chemical gradients that promote several types of chemical reactions, including oxidation-reduction reactions and precipitation reactions. ^[21] Because of these reactions, hydrothermal plumes are dynamic entities whose physical and chemical properties evolve over both space and time within the ocean.

Hydrothermal vent fluids harbor temperatures (~40 to >400 °C) well above that of ocean floor seawater (~4 °C), meaning that hydrothermal fluid is less dense than the surrounding seawater and will rise through the water column due to buoyancy, forming a hydrothermal plume; therefore, the phase during which hydrothermal plumes rise through the water column is known as the "buoyant plume" phase. ^[21] During this phase, shear forces between the hydrothermal plume and surrounding seawater generate turbulent flow that facilitates mixing between the two types of fluids, which progressively dilutes the hydrothermal plume with seawater. ^[21] Eventually, the coupled effects of dilution and rising into progressively warmer (less dense) overlying seawater will cause the hydrothermal plume to become neutrally buoyant at some height above the seafloor; therefore, this stage of hydrothermal plume evolution is known as the "nonbuoyant plume" phase. ^[21] Once the plume is neutrally buoyant, it can no longer continue to rise through the water column and instead begins to spread laterally throughout the ocean, potentially over several thousands of kilometers. ^[22]

Chemical reactions occur concurrently with the physical evolution of hydrothermal plumes. While seawater is a relatively oxidizing fluid, hydrothermal vent fluids are typically reducing in nature. ^[21] Consequently, reduced chemicals such as hydrogen gas, hydrogen sulfide, methane, Fe²⁺, and Mn²⁺ that are common in many vent fluids will react upon mixing with seawater. In fluids with high concentrations of H₂S, dissolved metal ions such as Fe²⁺ and Mn²⁺ readily precipitate as dark-colored metal sulfide minerals (see "black smokers"). ^[21] Furthermore, Fe²⁺ and Mn²⁺ entrained within the hydrothermal plume will eventually oxidize to form insoluble Fe and Mn (oxy)hydroxide minerals. ^[23] For this reason, the hydrothermal "near field" has been proposed to refer to the hydrothermal plume region undergoing active oxidation of metals while the term "far field" refers to the plume region within which complete metal oxidation has occurred. ^[22]

Ocean biogeochemistry

Hydrothermal plumes represent an important mechanism through which hydrothermal systems influence marine biogeochemistry. Hydrothermal vents emit a wide variety of trace metals into the ocean, including Fe, Mn, Cr, Cu, Zn, Co, Ni, Mo, Cd, V, and W, ^[25] many of which have biological functions. ^[26] Numerous physical and chemical processes control the fate of these metals once they are expelled into the water column. Based on thermodynamic theory, Fe²⁺ and Mn²⁺ should oxidize in seawater to form insoluble metal (oxy)hydroxide precipitates; however, complexation with organic compounds and the formation of colloids and nanoparticles can keep these redox-sensitive elements suspended in solution far from the vent site. ^{[21] [23]}

Fe and Mn often have the highest concentrations among metals in acidic hydrothermal vent fluids, ^[25] and both have biological significance, particularly Fe, which is often a limiting nutrient in marine environments. ^[26] Therefore, far-field transport of Fe and Mn via organic complexation may constitute an important mechanism of ocean metal cycling. ^[22] Additionally, hydrothermal vents deliver significant concentrations of other biologically important trace metals to the ocean such as Mo, which may have been important in the early chemical evolution of the Earth's oceans and to the origin of life (see "theory of hydrothermal origin of life"). ^{[25] [27]} However, Fe and Mn precipitates can also influence ocean biogeochemistry by removing trace metals from the water column. The charged surfaces of iron (oxy)hydroxide minerals effectively adsorb elements such as phosphorus, vanadium, arsenic, and rare earth metals from seawater; therefore, although hydrothermal plumes may represent a net source of metals such as Fe and Mn to the oceans, they can also scavenge other metals and non-metalliferous nutrients such as P from seawater, representing a net sink of these elements. ^[23]

Biology of hydrothermal vents

Life has traditionally been seen as driven by energy from the sun, but deep-sea organisms have no access to sunlight, so biological communities around hydrothermal vents must depend on nutrients found in the dusty chemical deposits and hydrothermal fluids in which they live. Previously, benthic oceanographers assumed that vent organisms were dependent on marine snow, as deep-sea organisms are. This would leave them dependent on plant life and thus the sun. Some hydrothermal vent organisms do consume this "rain", but with only such a system, life forms would be sparse. Compared to the surrounding sea floor, however, hydrothermal vent zones have a density of organisms 10,000 to 100,000 times greater. These organisms include yeti crabs, which have long hairy arms that they reach out over the vent to collect food with.^{[ citation needed ]}

The hydrothermal vents are recognized as a type of chemosynthetic based ecosystems (CBE) where primary productivity is fuelled by chemical compounds as energy sources instead of light (chemoautotrophy). ^[28] Hydrothermal vent communities are able to sustain such vast amounts of life because vent organisms depend on chemosynthetic bacteria for food. The water from the hydrothermal vent is rich in dissolved minerals and supports a large population of chemoautotrophic bacteria. These bacteria use sulfur compounds, particularly hydrogen sulfide, a chemical highly toxic to most known organisms, to produce organic material through the process of chemosynthesis.

The vents' impact on the living environment goes beyond the organisms that lives around them, as they act as a significant source of iron in the oceans, providing iron for the phytoplankton. ^[29]

Biological communities

Main articles: Deep sea communities, Earliest known life forms, Geyser § Biology of geysers, Hot spring § Biota in hot springs, and Hydrothermal vent microbial communities

Further information: Hyperthermophile and Thermophile

The oldest confirmed record of a "modern" biological community related with a vent is the Figueroa Sulfide, from the Early Jurassic of California. ^[30] The ecosystem so formed is reliant upon the continued existence of the hydrothermal vent field as the primary source of energy, which differs from most surface life on Earth, which is based on solar energy. However, although it is often said that these communities exist independently of the sun, some of the organisms are actually dependent upon oxygen produced by photosynthetic organisms, while others are anaerobic.

The chemosynthetic bacteria grow into a thick mat which attracts other organisms, such as amphipods and copepods, which graze upon the bacteria directly. Larger organisms, such as snails, shrimp, crabs, tube worms, fish (especially eelpout, cutthroat eel, Ophidiiformes and Symphurus thermophilus ), and octopuses (notably Vulcanoctopus hydrothermalis ), form a food chain of predator and prey relationships above the primary consumers. The main families of organisms found around seafloor vents are annelids, pogonophorans, gastropods, and crustaceans, with large bivalves, vestimentiferan worms, and "eyeless" shrimp making up the bulk of nonmicrobial organisms.^{[ citation needed ]}

Siboglinid tube worms, which may grow to over 2 m (6.6 ft) tall in the largest species, often form an important part of the community around a hydrothermal vent. They have no mouth or digestive tract, and like parasitic worms, absorb nutrients produced by the bacteria in their tissues. About 285 billion bacteria are found per ounce of tubeworm tissue. Tubeworms have red plumes which contain hemoglobin. Hemoglobin combines with hydrogen sulfide and transfers it to the bacteria living inside the worm. In return, the bacteria nourish the worm with carbon compounds. Two of the species that inhabit a hydrothermal vent are Tevnia jerichonana, and Riftia pachyptila . One discovered community, dubbed "Eel City", consists predominantly of the eel Dysommina rugosa . Though eels are not uncommon, invertebrates typically dominate hydrothermal vents. Eel City is located near Nafanua volcanic cone, American Samoa. ^[31]

In 1993, already more than 100 gastropod species were known to occur in hydrothermal vents. ^[32] Over 300 new species have been discovered at hydrothermal vents, ^[33] many of them "sister species" to others found in geographically separated vent areas. It has been proposed that before the North American Plate overrode the mid-ocean ridge, there was a single biogeographic vent region found in the eastern Pacific. ^[34] The subsequent barrier to travel began the evolutionary divergence of species in different locations. The examples of convergent evolution seen between distinct hydrothermal vents is seen as major support for the theory of natural selection and of evolution as a whole.

Although life is very sparse at these depths, black smokers are the centers of entire ecosystems. Sunlight is nonexistent, so many organisms, such as archaea and extremophiles, convert the heat, methane, and sulfur compounds provided by black smokers into energy through a process called chemosynthesis. More complex life forms, such as clams and tubeworms, feed on these organisms. The organisms at the base of the food chain also deposit minerals into the base of the black smoker, therefore completing the life cycle.

A species of phototrophic bacterium has been found living near a black smoker off the coast of Mexico at a depth of 2,500 m (8,200 ft). No sunlight penetrates that far into the waters. Instead, the bacteria, part of the Chlorobiaceae family, use the faint glow from the black smoker for photosynthesis. This is the first organism discovered in nature to exclusively use a light other than sunlight for photosynthesis. ^[35]

New and unusual species are constantly being discovered in the neighborhood of black smokers. The Pompeii worm Alvinella pompejana, which is capable of withstanding temperatures up to 80 °C (176 °F), was found in the 1980s, and a scaly-foot gastropod Chrysomallon squamiferum in 2001 during an expedition to the Indian Ocean's Kairei hydrothermal vent field. The latter uses iron sulfides (pyrite and greigite) for the structure of its dermal sclerites (hardened body parts), instead of calcium carbonate. The extreme pressure of 2,500 m of water (approximately 25  megapascals or 250  atmospheres) is thought to play a role in stabilizing iron sulfide for biological purposes. This armor plating probably serves as a defense against the venomous radula (teeth) of predatory snails in that community.

In March 2017, researchers reported evidence of possibly the oldest forms of life on Earth. Putative fossilized microorganisms were discovered in hydrothermal vent precipitates in the Nuvvuagittuq Belt of Quebec, Canada, that may have lived as early as 4.280 billion years ago, not long after the oceans formed 4.4 billion years ago, and not long after the formation of the Earth 4.54 billion years ago. ^{[36] [37] [38]}

Animal-bacterial symbiosis

Hydrothermal vent ecosystems have enormous biomass and productivity, but this rests on the symbiotic relationships that have evolved at vents. Deep-sea hydrothermal vent ecosystems differ from their shallow-water and terrestrial hydrothermal counterparts due to the symbiosis that occurs between macroinvertebrate hosts and chemoautotrophic microbial symbionts in the former. ^[39] Since sunlight does not reach deep-sea hydrothermal vents, organisms in deep-sea hydrothermal vents cannot obtain energy from the sun to perform photosynthesis. Instead, the microbial life found at hydrothermal vents is chemosynthetic; they fix carbon by using energy from chemicals such as sulfide, as opposed to light energy from the sun. In other words, the symbiont converts inorganic molecules (H₂S, CO₂, O) to organic molecules that the host then uses as nutrition. However, sulfide is an extremely toxic substance to most life on Earth. For this reason, scientists were astounded when they first found hydrothermal vents teeming with life in 1977. What was discovered was the ubiquitous symbiosis of chemoautotrophs living in (endosymbiosis) the vent animals' gills; the reason why multicellular life is capable to survive the toxicity of vent systems. Scientists are therefore now studying how the microbial symbionts aid in sulfide detoxification (therefore allowing the host to survive the otherwise toxic conditions). Work on microbiome function shows that host-associated microbiomes are also important in host development, nutrition, defense against predators, and detoxification. In return, the host provides the symbiont with chemicals required for chemosynthesis, such as carbon, sulfide, and oxygen.^{[ citation needed ]}

In the early stages of studying life at hydrothermal vents, there were differing theories regarding the mechanisms by which multicellular organisms were able to acquire nutrients from these environments, and how they were able to survive in such extreme conditions. In 1977, it was hypothesized that the chemoautotrophic bacteria at hydrothermal vents might be responsible for contributing to the diet of suspension-feeding bivalves. ^[40]

Finally, in 1981, it was understood that giant tubeworm nutrition acquisition occurred as a result of chemoautotrophic bacterial endosymbionts. ^{[41] [42] [43]} As scientists continued to study life at hydrothermal vents, it was understood that symbiotic relationships between chemoautotrophs and macrofauna invertebrate species was ubiquitous. For instance, in 1983, clam gill tissue was confirmed to contain bacterial endosymbionts; ^[44] in 1984 vent bathymodiolid mussels and vesicomyid clams were also found to carry endosymbionts. ^{[45] [46]}

However, the mechanisms by which organisms acquire their symbionts differ, as do the metabolic relationships. For instance, tubeworms have no mouth and no gut, but they do have a "trophosome", which is where they deal with nutrition and where their endosymbionts are found. They also have a bright red plume, which they use to uptake compounds such as O, H₂S, and CO₂, which feed the endosymbionts in their trophosome. Remarkably, the tubeworms hemoglobin (which incidentally is the reason for the bright red color of the plume) is capable of carrying oxygen without interference or inhibition from sulfide, despite the fact that oxygen and sulfide are typically very reactive. In 2005, it was discovered that this is possible due to zinc ions that bind the hydrogen sulfide in the tubeworms hemoglobin, therefore preventing the sulfide from reacting with the oxygen. It also reduces the tubeworms tissue from exposure to the sulfide and provides the bacteria with the sulfide to perform chemoautotrophy. ^[47] It has also been discovered that tubeworms can metabolize CO₂ in two different ways, and can alternate between the two as needed as environmental conditions change. ^[48]

In 1988, research confirmed thiotrophic (sulfide-oxidizing) bacteria in Alviniconcha hessleri, a large vent mollusk. ^[49] In order to circumvent the toxicity of sulfide, mussels first convert it to thiosulfate before carrying it over to the symbionts. ^[50] In the case of motile organisms such as alvinocarid shrimp, they must track oxic (oxygen-rich) / anoxic (oxygen-poor) environments as they fluctuate in the environment.^{[ citation needed ]}

Organisms living at the edge of hydrothermal vent fields, such as pectinid scallops, also carry endosymbionts in their gills, and as a result their bacterial density is low relative to organisms living nearer to the vent. However, the scallop's dependence on the microbial endosymbiont for obtaining their nutrition is therefore also lessened.^{[ citation needed ]}

Furthermore, not all host animals have endosymbionts; some have episymbionts—symbionts living on the animal as opposed to inside the animal. Shrimp found at vents in the Mid-Atlantic Ridge were once thought of as an exception to the necessity of symbiosis for macroinvertebrate survival at vents. That changed in 1988 when they were discovered to carry episymbionts. ^[51] Since then, other organisms at vents have been found to carry episymbionts as well, ^[52] such as Lepetodrilis fucensis. ^[53]

Furthermore, while some symbionts reduce sulfur compounds, others are known as "methanotrophs" and reduce carbon compounds, namely methane. Bathmodiolid mussels are an example of a host that contains methanotrophic endosymbionts; however, the latter mostly occur in cold seeps as opposed to hydrothermal vents.^{[ citation needed ]}

While chemosynthesis occurring at the deep ocean allows organisms to live without sunlight in the immediate sense, they technically still rely on the sun for survival, since oxygen in the ocean is a byproduct of photosynthesis. However, if the sun were to suddenly disappear and photosynthesis ceased to occur on our planet, life at the deep-sea hydrothermal vents could continue for millennia (until the oxygen was depleted).^{[ citation needed ]}

Discovery and exploration

In 1949, a deep water survey reported anomalously hot brines in the central portion of the Red Sea. Later work in the 1960s confirmed the presence of hot, 60 °C (140 °F), saline brines and associated metalliferous muds. The hot solutions were emanating from an active subseafloor rift. The highly saline character of the waters was not hospitable to living organisms. ^[87] The brines and associated muds are currently under investigation as a source of mineable precious and base metals.

In June 1976, scientists from the Scripps Institution of Oceanography obtained the first evidence for submarine hydrothermal vents along the Galápagos Rift, a spur of the East Pacific Rise, on the Pleiades II expedition, using the Deep-Tow seafloor imaging system. ^[88] In 1977, the first scientific papers on hydrothermal vents were published ^[89] by scientists from the Scripps Institution of Oceanography; research scientist Peter Lonsdale published photographs taken from deep-towed cameras, ^[90] and PhD student Kathleen Crane published maps and temperature anomaly data. ^[91] Transponders were deployed at the site, which was nicknamed "Clam-bake", to enable an expedition to return the following year for direct observations with the DSV Alvin.

Chemosynthetic ecosystems surrounding the Galápagos Rift submarine hydrothermal vents were first directly observed in 1977, when a group of marine geologists funded by the National Science Foundation returned to the Clambake sites. The principal investigator for the submersible study was Jack Corliss of Oregon State University. Corliss and Tjeerd van Andel from Stanford University observed and sampled the vents and their ecosystem on February 17, 1977, while diving in the DSV Alvin, a research submersible operated by the Woods Hole Oceanographic Institution (WHOI). ^[92] Other scientists on the research cruise included Richard (Dick) Von Herzen and Robert Ballard of WHOI, Jack Dymond and Louis Gordon of Oregon State University, John Edmond and Tanya Atwater of the Massachusetts Institute of Technology, Dave Williams of the U.S. Geological Survey, and Kathleen Crane of Scripps Institution of Oceanography. ^{[92] [93]} This team published their observations of the vents, organisms, and the composition of the vent fluids in the journal Science. ^[94] In 1979, a team of biologists led by J. Frederick Grassle, at the time at WHOI, returned to the same location to investigate the biological communities discovered two year earlier.

High temperature hydrothermal vents, the "black smokers", were discovered in spring 1979 by a team from the Scripps Institution of Oceanography using the submersible Alvin. The RISE expedition explored the East Pacific Rise at 21° N with the goals of testing geophysical mapping of the sea floor with the Alvin and finding another hydrothermal field beyond the Galápagos Rift vents. The expedition was led by Fred Spiess and Ken Macdonald and included participants from the U.S., Mexico and France. ^[17] The dive region was selected based on the discovery of sea floor mounds of sulfide minerals by the French CYAMEX expedition in 1978. ^[95]  Prior to dive operations, expedition member Robert Ballard located near-bottom water temperature anomalies using a deeply towed instrument package. The first dive was targeted at one of those anomalies. On Easter Sunday April 15, 1979 during a dive of Alvin to 2,600 meters, Roger Larson and Bruce Luyendyk found a hydrothermal vent field with a biological community similar to the Galápagos vents. On a subsequent dive on April 21, William Normark and Thierry Juteau discovered the high temperature vents emitting black mineral particle jets from chimneys; the black smokers. ^[96] Following this Macdonald and Jim Aiken rigged a temperature probe to Alvin to measure the water temperature at the black smoker vents. This observed the highest temperatures then recorded at deep sea hydrothermal vents (380±30 °C). ^[97] Analysis of black smoker material and the chimneys that fed them revealed that iron sulfide precipitates are the common minerals in the "smoke" and walls of the chimneys. ^[98]  

In 2005, Neptune Resources NL, a mineral exploration company, applied for and was granted 35,000 km² of exploration rights over the Kermadec Arc in New Zealand's Exclusive Economic Zone to explore for seafloor massive sulfide deposits, a potential new source of lead-zinc-copper sulfides formed from modern hydrothermal vent fields. The discovery of a vent in the Pacific Ocean offshore of Costa Rica, named the Medusa hydrothermal vent field (after the serpent-haired Medusa of Greek mythology), was announced in April 2007. ^[99] The Ashadze hydrothermal field (13°N on the Mid-Atlantic Ridge, elevation -4200 m) was the deepest known high-temperature hydrothermal field until 2010, when a hydrothermal plume emanating from the Beebe ^[100] site ( 18°33′N81°43′W / 18.550°N 81.717°W / 18.550; -81.717 , elevation -5000 m) was detected by a group of scientists from NASA Jet Propulsion Laboratory and Woods Hole Oceanographic Institution. This site is located on the 110 km long, ultraslow spreading Mid-Cayman Rise within the Cayman Trough. ^[101] In early 2013, the deepest known hydrothermal vents were discovered in the Caribbean Sea at a depth of almost 5,000 metres (16,000 ft). ^[102]

Oceanographers are studying the volcanoes and hydrothermal vents of the Juan de Fuca mid ocean ridge where tectonic plates are moving away from each other. ^[103]

Hydrothermal vents and other geothermal manifestations are currently being explored in the Bahía de Concepción, Baja California Sur, Mexico. ^[104]

Distribution

Hydrothermal vents are distributed along the Earth's plate boundaries, although they may also be found at intra-plate locations such as hotspot volcanoes. As of 2009 there were approximately 500 known active submarine hydrothermal vent fields, with about half visually observed at the seafloor and the other half suspected from water column indicators and/or seafloor deposits. ^[105]

Rogers et al. (2012) ^[106] recognized at least 11 biogeographic provinces of hydrothermal vent systems:

1. Mid-Atlantic Ridge province,
2. East Scotia Ridge province,
3. northern East Pacific Rise province,
4. central East Pacific Rise province,
5. southern East Pacific Rise province,
6. south of the Easter Microplate,
7. Indian Ocean province,
8. four provinces in the western Pacific and many more.

Exploitation

Hydrothermal vents, in some instances, have led to the formation of exploitable mineral resources via the deposition of seafloor massive sulfide deposits. The Mount Isa orebody, located in Queensland, Australia, is an excellent example. ^[107] Many hydrothermal vents are rich in cobalt, gold, copper, and rare earth metals essential for electronic components. ^[108] Hydrothermal venting on the Archean seafloor is considered to have formed Algoma-type banded iron formations, which have been a source of iron ore. ^[109]

Recently, mineral exploration companies, driven by the elevated price activity in the base metals sector during the mid-2000s, have turned their attention to the extraction of mineral resources from hydrothermal fields on the seafloor. Significant cost reductions are, in theory, possible. ^[110]

In countries such as Japan, where mineral resources are primarily derived from international imports, ^[111] there is a particular push for the extraction of seafloor mineral resources. ^[112] The world's first "large-scale" mining of hydrothermal vent mineral deposits was carried out by Japan Oil, Gas and Metals National Corporation (JOGMEC) in August – September, 2017. JOGMEC carried out this operation using the Research Vessel Hakurei. This mining was carried out at the 'Izena hole/cauldron' vent field within the hydrothermally active back-arc basin known as the Okinawa Trough, which contains 15 confirmed vent fields according to the InterRidge Vents Database.

Two companies are currently engaged in the late stages of commencing to mine seafloor massive sulfides (SMS). Nautilus Minerals is in the advanced stages of commencing extraction from its Solwarra deposit, in the Bismarck Archipelago, and Neptune Minerals is at an earlier stage with its Rumble II West deposit, located on the Kermadec Arc, near the Kermadec Islands. Both companies are proposing using modified existing technology. Nautilus Minerals, in partnership with Placer Dome (now part of Barrick Gold), succeeded in 2006 in returning over 10 metric tons of mined SMS to the surface using modified drum cutters mounted on an ROV, a world first. ^[113] Neptune Minerals in 2007 succeeded in recovering SMS sediment samples using a modified oil industry suction pump mounted on an ROV, also a world first. ^[114]

Potential seafloor mining has environmental impacts, including dust plumes from mining machinery affecting filter-feeding organisms, ^[108] collapsing or reopening vents, methane clathrate release, or even sub-oceanic land slides. ^[115]

There are also potential environmental effects from the tools needed for mining these hydrothermal vent ecosystems, including noise pollution and anthropogenic light. Hydrothermal vent system mining would require the use of both submerged mining tools on the seafloor, including remotely operated underwater vehicles (ROVs), as well as surface support vessels on the ocean surface. ^[116] Inevitably, through the operation of these machines, some level of noise will be created, which presents a problem for hydrothermal vent organisms because, as they are up to 12,000 feet below the surface of the ocean, they experience very little sound. ^[116] As a result of this, these organisms have evolved to have highly sensitive hearing organs, so if there is a sudden increase in noise, such as that created by mining machinery, there is potential to damage these auditory organs and harm the vent organisms. ^[116] It is also important to consider that many studies have been able to show that a large percent of benthic organisms communicate using very low-frequency sounds; therefore, increasing ambient noise levels on the seafloor could potentially mask communication between the organisms and alter behavioral patterns. ^[116] Similar to how deep-sea SMS mining tools create noise pollution, they also create anthropogenic light sources on the seafloor (from mining tools) and the ocean surface (from surface support vessels). Organisms at these hydrothermal vent systems are in the aphotic zone of the ocean and have adapted to very low light conditions. Studies on deep sea shrimp have shown the potential for flood lights used on the sea floor used in studying the vent systems to cause permanent retinal damage, ^[116] warranting further research into the potential risk to other vent organisms. On top of the risk presented to deep-sea organisms, the surface support vessels use nocturnal anthropogenic lighting. ^[116] Research has shown that this type of lighting on the ocean surface can disorient seabirds and cause fallout, where they fly toward the anthropogenic light and become exhausted or collide with man-made objects, resulting in injury or death. ^[116] There is consideration for both aquatic and land organisms when evaluating the environmental effects of hydrothermal vent mining.

There are three mining waste processes, known as the side cast sediment release, dewatering process, and sediment shift or disturbance, that would be expected with the deep-sea mining processes and could result in the accumulation of a sediment plume or cloud, which can have substantial environmental implications. The side cast sediment release is a process that would occur at the seafloor and would involve the move of material at the seafloor by the submerged ROV's and would most likely contribute to the formation of sediment plumes at the seafloor. ^[116] The idea of side cast release is that the ROV's would discard economically invaluable material to the side of the mining sight before transporting the sulfide material to the supporting vessel at the surface. The goal of this process is to reduce the amount of material being transferred to the surface and minimize land-based. ^[116] The dewatering process is a mining waste process that would most likely contribute to the formation of sediment plumes from the surface. The method of mine waste disposal releases water from the ship that may have been obtained during the extraction and transport of the material from the seafloor to the surface. The third contribution to the formation of the sediment plume or cloud would be sediment disturbance and release. This mining waste contribution is mainly associated with the mining activity on the seafloor associated with the movement of the ROVs and the destructive disturbance of the seafloor as part of the mining process itself. ^[116]

The two main environmental concerns as a result of these waste mining processes that contribute to the formation of the sediment plume would be the release of heavy metals and increased amounts of sediment released. The release of heavy metals is mainly associated with the dewatering process that would take place on board the ship at the surface of the water. ^[116] The main problem associated with dewatering is that it is not just the release of seawater re-entering the water column. Heavy metals such as copper and cobalt that would be sourced from the material extracted on the seafloor are also mixed in with the water that is released into the water column. The first environmental concern associated with the release of heavy metals is that it has the potential to change ocean chemistry within that localized water column area. The second concern would be that some of the heavy metals that could be released can have some level of toxicity to not only organisms inhabiting that area but also organisms passing through the mining site area. ^[116] The concerns surrounding increased sediment release are mainly related to the other two mining waste processes, side cast sediment and seafloor sediment disturbance. The main environmental concern would be the smothering of organisms below as a result of redistributing large amounts of sediment to other areas on the seafloor, which could potentially threaten the population of organisms inhabiting the area. Redistribution of large quantities of sediment can also affect the feeding and gas exchange processes between organisms, posing a serious threat to the population. Finally, these processes can also increase the sedimentation rate on the seafloor, resulting in a predicted minimum of 500 m per every 1–10 km. ^[116]

A large amount of work is currently being engaged in by both of the above-mentioned companies to ensure that the potential environmental impacts of seafloor mining are well understood and control measures are implemented before exploitation commences. ^[117] However, this process has been arguably hindered by the disproportionate distribution of research effort among vent ecosystems; the best studied and understood hydrothermal vent ecosystems are not representative of those targeted for mining. ^[118]

Attempts have been made in the past to exploit minerals from the seafloor. The 1960s and 1970s saw a great deal of activity (and expenditure) in the recovery of manganese nodules from the abyssal plains, with varying degrees of success. This does demonstrate, however, that the recovery of minerals from the seafloor is possible and has been possible for some time. Mining of manganese nodules served as a cover story for the elaborate attempt in 1974 by the CIA to raise the sunken Soviet submarine K-129 using the Glomar Explorer, a ship purpose-built for the task by Howard Hughes. ^[119] The operation was known as Project Azorian, and the cover story of seafloor mining of manganese nodules may have served as the impetus to propel other companies to make the attempt.

Conservation

The conservation of hydrothermal vents has been the subject of sometimes heated discussion in the oceanographic community for the last 20 years. ^[120] It has been pointed out that it may be that those causing the most damage to these fairly rare habitats are scientists. ^{[121] [122]} There have been attempts to forge agreements over the behaviour of scientists investigating vent sites, but, although there is an agreed code of practice, there is no formal international and legally binding agreement. ^[123]

Conservation of hydrothermal vent ecosystems after the fact of mining of an active system would depend on the recolonization of chemosynthetic bacteria, and therefore the continuation of the hydrothermal vent fluid as it is the main hydrothermal energy source. ^[116] It is very difficult to get an idea of the effects of mining on the hydrothermal vent fluid because there have been no large scale studies done. ^[116] However, there have been studies on the recolonization of these vent ecosystems after volcanic destruction. ^[124] From these we can develop insight on the potential effects of mining destruction, and have learned it took 3–5 years for bacteria to recolonize the area, and around 10 years for megafauna to return. ^[124] It was also found that there was a shift in the composition of species in the ecosystem compared to before the destruction, and the presence of immigrant species. ^[116] Though further research into the effects of sustained seafloor SMS mining on species recolonization is needed.

Geochronological dating

Common methods to find out the ages of hydrothermal vents are to date the sulfide (e.g., pyrite) and sulphate minerals (e.g., baryte). ^{[125] [126] [127] [128] [129]} Common dating methods include radiometric dating ^{[125] [126]} and electron spin resonance dating. ^{[127] [128] [129]} Different dating methods have their own limitations, assumptions and challenges. General challenges include the high purity of extracted minerals required for dating, the age range of each dating method, heating above closure temperatures erasing ages of older minerals, and multiple episodes of mineral formation resulting in a mixture of ages. In environments with multiple phases of mineral formation, generally, electron spin resonance dating gives the average age of the bulk mineral while radiometric dates are biased to the ages of younger phases because of the decay of parent nuclei. These explain why different methods can give different ages to the same sample and why the same hydrothermal chimney can have samples with different ages. ^{[128] [129] [130]}

See also

• Abiogenesis  – Life arising from non-living matter
• Brine pool  – Accumulation of brine in a seafloor depression
• Endeavour Hydrothermal Vents  – Group of Pacific Ocean hydrothermal vents
• Extremophiles  – Organisms capable of living in extreme environmentsPages displaying short descriptions of redirect targets
• Hydrogen sulfide chemosynthesis - system of generating energy used in hydrothermal vents
• Lost City Hydrothermal Field
• Magic Mountain (British Columbia)  – Hydrothermal vent field on the Southern Explorer Ridge, west of Vancouver Island, British Columbia
• 9° North  – Region of hydrothermal vents on the East Pacific Rise in the Pacific Ocean
• Pito Seamount  – Seamount in the Pacific Ocean north-northwest of Easter Island
• Submarine volcano  – Underwater vents or fissures in the Earth's surface from which magma can erupt
• Volcanogenic massive sulfide ore deposit , also known as VMS deposit – Metal sulfide ore deposit
• Deep sea mining

Related Research Articles

The iron–sulfur world hypothesis is a set of proposals for the origin of life and the early evolution of life advanced in a series of articles between 1988 and 1992 by Günter Wächtershäuser, a Munich patent lawyer with a degree in chemistry, who had been encouraged and supported by philosopher Karl R. Popper to publish his ideas. The hypothesis proposes that early life may have formed on the surface of iron sulfide minerals, hence the name. It was developed by retrodiction from extant biochemistry in conjunction with chemical experiments.

A cold seep is an area of the ocean floor where seepage of fluids rich in hydrogen sulfide, methane, and other hydrocarbons occurs, often in the form of a brine pool. Cold does not mean that the temperature of the seepage is lower than that of the surrounding sea water; on the contrary, its temperature is often slightly higher. The "cold" is relative to the very warm conditions of a hydrothermal vent. Cold seeps constitute a biome supporting several endemic species.

Riftia pachyptila, commonly known as the giant tube worm and less commonly known as the giant beardworm, is a marine invertebrate in the phylum Annelida related to tube worms commonly found in the intertidal and pelagic zones. R. pachyptila lives on the floor of the Pacific Ocean near hydrothermal vents. The vents provide a natural ambient temperature in their environment ranging from 2 to 30 °C, and this organism can tolerate extremely high hydrogen sulfide levels. These worms can reach a length of 3 m, and their tubular bodies have a diameter of 4 cm (1.6 in).

An abyssal plain is an underwater plain on the deep ocean floor, usually found at depths between 3,000 and 6,000 metres. Lying generally between the foot of a continental rise and a mid-ocean ridge, abyssal plains cover more than 50% of the Earth's surface. They are among the flattest, smoothest, and least explored regions on Earth. Abyssal plains are key geologic elements of oceanic basins.

The seabed is the bottom of the ocean. All floors of the ocean are known as 'seabeds'.

The Lost City Hydrothermal Field, often referred to simply as Lost City, is an area of marine alkaline hydrothermal vents located on the Atlantis Massif at the intersection between the Mid-Atlantic Ridge and the Atlantis Transform Fault, in the Atlantic Ocean. It is a long-lived site of active and inactive ultramafic-hosted serpentinization, abiotically producing many simple molecules such as methane and hydrogen which are fundamental to microbial life. As such it has generated scientific interest as a prime location for investigating the origin of life on Earth and other planets similar to it.

The important sulfur cycle is a biogeochemical cycle in which the sulfur moves between rocks, waterways and living systems. It is important in geology as it affects many minerals and in life because sulfur is an essential element (CHNOPS), being a constituent of many proteins and cofactors, and sulfur compounds can be used as oxidants or reductants in microbial respiration. The global sulfur cycle involves the transformations of sulfur species through different oxidation states, which play an important role in both geological and biological processes. Steps of the sulfur cycle are:

Sedimentary exhalative deposits are zinc-lead deposits originally interpreted to have been formed by discharge of metal-bearing basinal fluids onto the seafloor resulting in the precipitation of mainly stratiform ore, often with thin laminations of sulfide minerals. SEDEX deposits are hosted largely by clastic rocks deposited in intracontinental rifts or failed rift basins and passive continental margins. Since these ore deposits frequently form massive sulfide lenses, they are also named sediment-hosted massive sulfide (SHMS) deposits, as opposed to volcanic-hosted massive sulfide (VHMS) deposits. The sedimentary appearance of the thin laminations led to early interpretations that the deposits formed exclusively or mainly by exhalative processes onto the seafloor, hence the term SEDEX. However, recent study of numerous deposits indicates that shallow subsurface replacement is also an important process, in several deposits the predominant one, with only local if any exhalations onto the seafloor. For this reason, some authors prefer the term clastic-dominated zinc-lead deposits. As used today, therefore, the term SEDEX is not to be taken to mean that hydrothermal fluids actually vented into the overlying water column, although this may have occurred in some cases.

Paralvinella sulfincola, also known as the Sulfide worm, is a species of polychaete worm of the Alvinellidae family that thrives on undersea hot-water vents. It dwells within tubes in waters surrounding hydrothermal vents, in close proximity to super-heated fluids reaching over 300 °C (572 °F). The upper thermal limit for this polychaete is unknown; however, it is unlikely they can survive in constant temperatures over 50 °C (122 °F). It may tentatively be named a metazoan extremophile or, more specifically, a thermophile.

Seafloor massive sulfide deposits or SMS deposits, are modern equivalents of ancient volcanogenic massive sulfide ore deposits or VMS deposits. The term has been coined by mineral explorers to differentiate the modern deposit from the ancient.

Deep sea mining is the extraction of minerals from the seabed of the deep sea. The main ores of commercial interest are polymetallic nodules, which are found at depths of 4–6 km (2.5–3.7 mi) primarily on the abyssal plain. The Clarion–Clipperton zone (CCZ) alone contains over 21 billion metric tons of these nodules, with minerals such as copper, nickel, and cobalt making up 2.5% of their weight. It is estimated that the global ocean floor holds more than 120 million tons of cobalt, five times the amount found in terrestrial reserves.

Loki's Castle is a field of five active hydrothermal vents in the mid-Atlantic Ocean, located at 73 degrees north on the Mid-Atlantic Ridge between Iceland and Svalbard at a depth of 2,352 metres (7,717 ft). When they were discovered in mid-July 2008, they were the most northerly black smoker vents known to science.

The Endeavour Hydrothermal Vents are a group of hydrothermal vents in the north-eastern Pacific Ocean, located 260 kilometres (160 mi) southwest of Vancouver Island, British Columbia, Canada. The vent field lies 2,250 metres (7,380 ft) below sea level on the northern Endeavour segment of the Juan de Fuca Ridge. In 1982, dredged sulfide samples were recovered from the area covered in small tube worms and prompted a return to the vent field in August 1984, where the active vent field was confirmed by HOV Alvin on leg 10 of cruise AII-112.

A deep-sea community is any community of organisms associated by a shared habitat in the deep sea. Deep sea communities remain largely unexplored, due to the technological and logistical challenges and expense involved in visiting this remote biome. Because of the unique challenges, it was long believed that little life existed in this hostile environment. Since the 19th century however, research has demonstrated that significant biodiversity exists in the deep sea.

The Beebe Hydrothermal Vent Field is the world's deepest known hydrothermal vent site and is located just south of Grand Cayman in the Caribbean, on the north side of the Mid-Cayman Spreading Centre in the Cayman Trough. Approximately 24 kilometres (15 mi) south of Beebe is the Von Damm Vent Field.

The Rainbow hydrothermal vent field is a system of ultramafic-hosted hydrothermal vents located at 36°14'N on the Mid-Atlantic Ridge (MAR). It was discovered in 1994 from temperature readings of ten high-temperature black smokers at a depth of approximately 2.3 kilometres (1.4 mi), where fluids can exceed 365 °C (689 °F). The site is shallower and larger in area than many other vent fields along the Azores section of the MAR with an area of 1.5 square kilometres. Located 370 km (229.91 mi) southeast of Faial Island, it is a popular geochemical sampling and modeling site due to close proximity to the Azores and definitive representation of serpentinization from hydrothermal circulation and synthesis.

Hydrothermal mineral deposits are accumulations of valuable minerals which formed from hot waters circulating in Earth's crust through fractures. They eventually produce metallic-rich fluids concentrated in a selected volume of rock, which become supersaturated and then precipitate ore minerals. In some occurrences, minerals can be extracted for a profit by mining. Discovery of mineral deposits consumes considerable time and resources and only about one in every one thousand prospects explored by companies are eventually developed into a mine. A mineral deposit is any geologically significant concentration of an economically useful rock or mineral present in a specified area. The presence of a known but unexploited mineral deposit implies a lack of evidence for profitable extraction.

The hydrothermal vent microbial community includes all unicellular organisms that live and reproduce in a chemically distinct area around hydrothermal vents. These include organisms in the microbial mat, free floating cells, or bacteria in an endosymbiotic relationship with animals. Chemolithoautotrophic bacteria derive nutrients and energy from the geological activity at Hydrothermal vents to fix carbon into organic forms. Viruses are also a part of the hydrothermal vent microbial community and their influence on the microbial ecology in these ecosystems is a burgeoning field of research.

The RISE Project (Rivera Submersible Experiments) was a 1979 international marine research project which mapped and investigated seafloor spreading in the Pacific Ocean, at the crest of the East Pacific Rise (EPR) at 21° north latitude. Using a deep sea submersible (ALVIN) to search for hydrothermal activity at depths around 2600 meters, the project discovered a series of vents emitting dark mineral particles at extremely high temperatures which gave rise to the popular name, "black smokers". Biologic communities found at 21° N vents, based on chemosynthesis and similar to those found at the Galapagos spreading center, established that these communities are not unique. Discovery of a deep-sea ecosystem not based on sunlight spurred theories of the origin of life on Earth.

The Von Damm Hydrothermal Field is a field of hydrothermal vents located just south of Grand Cayman in the Caribbean, on the Mid-Cayman Rise in the Cayman Trough. It is approximately 24 kilometres (15 mi) south of the Beebe Vent Field. The vent field is named in commemoration of geochemical oceanographer Karen Von Damm, who died in 2008.

References

Further reading

• Haymon, R.M. (2014). "Hydrothermal Vents at Mid-Ocean Ridges". Reference Module in Earth Systems and Environmental Sciences. doi:10.1016/b978-0-12-409548-9.09050-3. ISBN   978-0-12-409548-9.
• Van Dover, C. L.; Humphris, SE; Fornari, D; Cavanaugh, CM; Collier, R; Goffredi, SK; Hashimoto, J; Lilley, MD; Reysenbach, AL; Shank, TM; Von Damm, KL; Banta, A; Gallant, RM; Gotz, D; Green, D; Hall, J; Harmer, TL; Hurtado, LA; Johnson, P; McKiness, ZP; Meredith, C; Olson, E; Pan, IL; Turnipseed, M; Won, Y; Young CR, 3rd; Vrijenhoek, RC (13 September 2001). "Biogeography and Ecological Setting of Indian Ocean Hydrothermal Vents". Science. 294 (5543): 818–823. Bibcode:2001Sci...294..818V. doi: 10.1126/science.1064574 . PMID   11557843. S2CID   543841.{{cite journal}}: CS1 maint: numeric names: authors list (link)
• Van Dover; Cindy Lee (2000). The Ecology of Deep-Sea Hydrothermal Vents. Princeton University Press. ISBN   978-0-691-04929-8.
• Beatty, J. T.; Overmann, J.; Lince, M. T.; Manske, A. K.; Lang, A. S.; Blankenship, R. E.; Van Dover, C. L.; Martinson, T. A.; Plumley, F. G. (20 June 2005). "An obligately photosynthetic bacterial anaerobe from a deep-sea hydrothermal vent". Proceedings of the National Academy of Sciences. 102 (26): 9306–9310. Bibcode:2005PNAS..102.9306B. doi: 10.1073/pnas.0503674102 . PMC   1166624 . PMID   15967984.
• Glyn Ford and Jonathan Simnett, Silver from the Sea, September/October 1982, Volume 33, Number 5, Saudi Aramco World Archived 2006-11-12 at the Wayback Machine Accessed 17 October 2005
• Ballard, Robert D., 2000, The Eternal Darkness, Princeton University Press.
• Csotonyi, J. T.; Stackebrandt, E.; Yurkov, V. (4 July 2006). "Anaerobic Respiration on Tellurate and Other Metalloids in Bacteria from Hydrothermal Vent Fields in the Eastern Pacific Ocean". Applied and Environmental Microbiology. 72 (7): 4950–4956. Bibcode:2006ApEnM..72.4950C. doi:10.1128/AEM.00223-06. PMC   1489322 . PMID   16820492.
• Koschinsky, Andrea; Garbe-Schönberg, Dieter; Sander, Sylvia; Schmidt, Katja; Gennerich, Hans-Hermann; Strauss, Harald (2008). "Hydrothermal venting at pressure-temperature conditions above the critical point of seawater, 5°S on the Mid-Atlantic Ridge". Geology. 36 (8): 615. Bibcode:2008Geo....36..615K. doi:10.1130/G24726A.1.
• Catherine Brahic (4 August 2008). "Found: The hottest water on Earth". New Scientist. Retrieved 18 June 2010.

External links

Wikimedia Commons has media related to Hydrothermal vents .

Scholia has a topic profile for Hydrothermal vent .

• InterRidge Vents Database – global database of the locations of known active submarine hydrothermal vent fields, hosted by InterRidge
• Ocean Explorer – public outreach site for explorations sponsored by the US Office of Ocean Exploration
• Video by EV Nautilus
• Video by Schmidt Ocean