Hydrothermal vents are fissures in a planet's surface from which geothermally heated water issues. Hydrothermal vents are commonly found in places that are also volcanically active, where hot magma is relatively near the planet's surface.

Hydrothermal vents are abundant on Earth because it is both geologically active and has large amounts of water on its surface. Common land types include hot springs, fumaroles and geysers. The most famous hydrothermal vent system is probably Yellowstone National Park in the United States.

Submarine hydrothermal vents (black smokers) were discovered in 1977. Despite their inaccessible location on ocean floors, many have been thoroughly mapped and explored. Relative to the majority of the deep sea, the areas around hydrothermal vents are biologically productive, often hosting complex communities fueled by the chemicals dissolved in the vent fluids. Chemosynthetic archaea form the base of the food chain, supporting diverse organisms, including giant tube worms, clams, and shrimp.

The water that issues from hydrothermal vents consists mostly of ground water that has percolated down into hot regions from the surface, but it also commonly contains some portion of primordial water that originated deep underground and is only now surfacing for the first time. The proportion varies from location to location.

Hydrothermal vents have been speculated to exist on Mars, and are believed to exist on Europa.

See also

• Cold seep
• Hot springs
• Fumarole
• Geyser
• Black smoker

External link

• A new type of hydrothermal vent http://www.washington.edu/newsroom/news/2000archive/12-00archive/k121200.html
• Vent geochemistry http://www.pmel.noaa.gov/vents/chemistry/circulation.html