ALVIN, an ONR-research submersible (a
small submarine) operated by Woods Hole Oceanographic Institute,
made an amazing discover in 1977. While diving nearly 8,000 feet
(2,400 meters) on the East Pacific Rise near the Pacific Ocean's
Galapagos Islands, the submersible and its three passengers happened
upon a hydrothermal vent, the first ever
seen by humans! Completely isolated from the world of light, whole
communities of organisms (creatures) live
in places where warm water flows from chimneys in the ocean floor.
These vents are found in some of the deepest places in the ocean,
far beyond the reach of normal submarines or divers.
Hydrothermal vents are formed where two
oceanic plates pull apart and erupting lava
replaces the sea floor.
In these areas, extremely hot, mineral-rich fluid flows out from
underneath the ocean floor's surface. The hot fluid flows into very
cold water, usually 2 C, and cools down quickly. The cooled minerals
in the fluid settle around the vent opening creating chimney-like
formations. Some chimneys have been known to grow as tall as 6
Cold seeps are areas similar to hydrothermal
vents. Though the cold seep waters are about the same temperature as
the surrounding waters, they are called cold seeps in contrast to the
extremely hot fluids from hydrothermal vents. The cold seeps support
organisms similar to the hydrothermal vents though the exact make-up
of the biological community surrounding them depends on the chemicals,
such as hydrogen sulfide, methane, iron, manganese and silica, found
in the cold-seep fluid.