Hydrothermal Vents

Imagine being on the ocean floor. You are in total darkness and in unbearable
pressure. You would think that in this freezing environment there is no life,
but there is. Eight years ago something was discovered that no one could even
imagine. It was a source of life called a hydrothermal vent. A hydrothermal vent
is a hot spring found at depths from three to four thousand meters in areas
along mid-ocean ridges. Plate movements occurring on the earth’s crust create
vents. They cause the surrounding water to increase to high levels of
temperature and also release large quantities of hydrogen sulfide in the form of
black smoke. Hydrothermal vents are located in the midnight zone of the ocean.

The midnight zone is mostly planes. There is a low concentration of oxygen
because of all the pressure. The pressure exceeds to about ten thousand tons per
inch. The midnight zone is a therophillic environment. This means that the
entire zone revolves around hydrothermal vents. There are many creatures in the
midnight zone. Tripod fish have three stick-like legs, which are used to find
remains of dead animals. Limpets are eel-like creatures that have a soft head,
which is used for moving around small rocks. Tube worms (pollychaet worms) are
truly amazing. They live off the bacteria produced in there own body! This
process is known as chemosythesis. Chemosythesis is the process in which a
deep-sea dweller lives off its own bacteria. It gathers chemicals from
hydrothermal vents and filters out the bacteria, forming a thick layer around
its mouthparts. Tube- worms and sponges are the only creatures that resemble
plants in any way in the midnight zone. Other deep-sea dwellers include clams,
mussels, eelpout and shrimp. We study hydrothermal vents with many different
methods. One way is to use submersibles. Submersibles are sea crafts that can
carry people to the depths of the ocean. A towed camera system is usually
attached to it. A sonar scan can pinpoint the exact location of the vent. R.O.Vs
and A.U.V.s are underwater computer controlled cars. They can travel underwater
faster than a submersible. Probably the most used method is a seabeam multibeam
sonar bathysetry. Alvin is the best submersible for underwater exploration.

Jason Jr. is attached to Alvin. Alvin (operated by Woods Hole) went down with
the Triste and Japans Kaiko to explore the midnight zone. This is when
hydrothermal vents were discovered. The Nautle is the closest to their
accomplishment. These are all submersibles that can enter the midnight zone. The

Cyana, Archiméde and DSRV-1 are the only submersibles that have tried to enter
the midnight zone. Deep-sea vents are found in all of the world’s oceans, near
hot spots and around active volcanoes. They can not be found one mile up from
the ocean’s floor. The most famous place to find them it between the tectonic
plates. In conclusion, hydrothermal vents have linked to the thought of life on
other planets because they support life in dark, pressured environment, where
there is a low concentration of oxygen and the temperature hovers around 0º


http://www.geneso.edu/~jc99/hydro.html http://hyperion.advanced.org/18828/data/db_2.html
http://www.pmel.noaa.gov/vents/geology/methods.html http://wwwyrbe.edu.on.ca/~mdhs/compscl/dpt3ar/oceanog/ahydrovt.html
http://www.geneso.edu/~jc99/whatarethey.html http://mbgnet.mobot.org/salt/oceans/zone.html

BOOKS Under The Sea, The Nature Company Discoveries Library, PP.32-33 Mysteries
of the Sea, By Perrine, Doug, Publications International, LTD PP. 239,302, OTHER

World Book Science Year 200, PP.237 World Ocean Floors-Pacific Ocean, Shupe,

John Washington, D.C., June 1992