Black smoker

"A hydrothermal vent is a geyser on the seafloor. It continuously spews super-hot, mineral-rich water that helps support a diverse community of organisms. Although most of the deep sea is sparsely populated, vent sites teem with a fascinating array of life. Tubeworms and huge clams are the most distinctive inhabitants of Pacific Ocean vent sites, while eyeless shrimp are found only at vents in the Atlantic Ocean. The first hydrothermal vent was discovered in 1977. They are known to exist in the Pacific and Atlantic oceans. Most are found at an average depth of about 7,000 feet (2,100 meters) in areas of seafloor spreading along the Mid-Ocean Ridge System — the underwater mountain chain that snakes its way around the globe. How do hydrothermal vents form? In some areas along the Mid-Ocean Ridge, the gigantic plates that form the Earth's crust are moving apart, creating cracks and crevices in the ocean floor. Seawater seeps into these openings and is heated by the molten rock, or magma, that lies beneath the Earth's crust. As the water is heated, it rises and seeks a path back out into the ocean through an opening in the seafloor.As the vent water bursts out into the ocean, its temperature may be as high as 750°F (400°C). Yet this water does not boil because it is under so much pressure from the tremendous weight of the ocean above. When the pressure on a liquid is increased, its boiling point goes up." -craig cary