Habitats: Hydrothermal Vent – Characteristics

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.

See a vent in action and an animation of an eruption and its impact.

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.

 

Animals living around hydrothermal vents rely on sunlight for food.
False
Hydrothermal vents are so deep, sunlight does not reach them. Animals around the vents rely on chemosynthesis, which is a process where bacteria convert sulfur found in the vent’s fluids into energy.
True
Nope!

The water flowing out of hydrothermal vents is usually very cold, about 2 degrees Celsius.
False
The water flowing out of hydrothermal vents is usually very hot. The surrounding water is about 2 degrees Celsius.
True
No way!
Tubeworms do not have mouths. How do they get nourishment?
Chemosynthetic bacteria
Cold seeps
No, try again.
Photosynthesis
Keep trying.
When were hydrothermal vents discovered?
1977
Scientists aboard ALVIN found hydrothermal vents while diving nearly 8,000 feet (2,400 meters) on the East Pacific Rise near the Pacific Ocean’s Galapagos Islands.
1902
No, try again.
1492
Keep trying.
What is the difference between hydrothermal vents and cold seeps?
Hydrothermal vents emit hot water, while cold seeps emit water that is same temperature as the surrounding water.
Exactly!
There is no difference.
Try again.
Cold seeps are found in very, very deep water while hydrothermal vents are found in very, very shallow water.
Keep searching!
Cold seeps do not really exist, while hydrothermal vents are only found on Mars.
No!

 

(source – because flash wasn’t working on the first page)