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.
See a hydrothermal vent.
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 kilometers!
What’s happening? Take a look at all the parts of this diagram.
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.
Now read this page and click the arrow to read the following page as well.
(source – because flash wasn’t working on the first page)