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Hydrothermal vents

Extreme environment

Pressure exceeding 250 Atmospheres.

(250 times more than normal atmospheric pressure).


Depth of 2500 to 3500 m.

(Bathypelagic zone and Abyssal zone).


Extremely temperature from 100°C to 400°C 

(High thermal shock with the 2°C seawater temperature).


High levels of toxic elements in most of the creatures on this planet

(hydrogen sulfide, methane, and metal sulfides.)


Low level of light level.


Low level of oxygen.

A hydrothermal vent is a fissure on the seafloor, typically found near volcanically active areas such as mid-ocean ridges, from which chimneys release geothermally heated water. These vent chimneys emit buoyant hydrothermal plumes of mineral-rich fluid.

These plumes form when seawater seeps into the Earth's crust, superheats from underlying magma, and then emerges, carrying dissolved metals and minerals like sulfur and iron. As the plumes rise and cool, they disperse nutrients and chemicals, profoundly influencing unique deep-sea ecosystems and biogeochemical cycles, which is a pathway through which elements circulate between living organisms, geological processes, and the environment. 

The formation of a vent chimney begins with mineral precipitation from expelled substances, solidifying upon contact with seawater to form sulfide ore rocks. These deposits result from decreasing seawater temperature, pressure loss, and oxidation. Over time, they develop into massive sulfide ore deposits, sometimes spanning hundreds of square kilometres and extending over one kilometre in depth.

Hydrothermal plumes significantly impact marine biogeochemistry by releasing sulfur compounds such as hydrogen sulfide (H₂S) into the ocean. Sulfur compounds are integral to marine biogeochemical cycles and deep-sea ecosystems. These sulfides are hypothesized to contribute to prebiotic chemistry and the origin of life. 

They support the growth of chemosynthetic bacteria, by serving as electron donors or acceptors in microbial metabolism. Marine phytoplankton and bacteria incorporate sulfur into their biomass. 

Life under hydrothermal vents exhibits immense biomass and productivity, supported by unique symbiotic relationships. Unlike surface and terrestrial hydrothermal systems, deep-sea vents rely on symbiosis between macroinvertebrate hosts and chemoautotrophic microbial symbionts.

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