Noun
English Wikipedia has an article on:hydrothermal ventWikipedia
hydrothermal vent (plural hydrothermal vents)
a hot spring, on the floor of the ocean, mostly along the central axes of the mid-ocean ridges, where heated fluids emerge from fissures in the Earth's crust.
The energy of this sunlight supports almost all life Hydrothermal vent communities live so deep under the sea that they have no access to sunlight. Source: Internet