Hydrothermal vent

On the ground, a volcano exists. The crack which the water heated with heat of the earth spouts is in deep sea as well as it. The name is Hydrothermal vent. They mainly have volcanic activity in an active place.


　Even if it calls it Hydrothermal vent at a word, especially the thing of deep sea is characteristic.
First, a biological activity is very prosperous. It is because many chemical substances have melted into the liquid which blew off. Furthermore, only one kind is not breeding and various kinds of living things form society intricately.

The society which surrounds this Hydrothermal vent is greatly dependent on bacteria and Archea. Bacteria are increased in large quantities, thanks to the chemical substance blowing off. Then, it increases and bacteria spread in thick mat. Then, the living thing which makes this food flocks. Furthermore, a food chain is formed when a big living thing preys on it.
　Moreover, this bacteria and relation of a tube worm are deep. They make bacteria parasitic on the inside of the body. It is each digestive function which a tube worm and bacteria have, and is living together well.


Thus, Hydrothermal vent is called source of the life of a living thing. Two or more hypotheses that the life was born from here also actually exist.

　Let's investigate in detail about a tube worm. Structure of their body is very interesting. It has the mouth and no alimentary canal. Gills is used in order to take in nutrition. Although they are not fish, either, where on earth is gills? Please see a right photograph. The reddest portion at a tip is gills. Is what was being imagined differed from considerably? A substance is absorbed from here and an organic matter is compounded in a body.




　A hydrothermal venting hole is often called a chimney from the figure projected from the ground. Then, what degree is the temperature of the "hot water" which blows off from the chimney really? Ashore, water boils at 100 ℃.
If it evaporates, water will become vapor and will be gas. That is, water (hot water) 100 ℃ or more should not be made.
　However, if something melts or big pressure is applied into water, the boiling point of water will go up. Is this surprised? Near the seabed with a chimney requires terrestrial big pressure about 200 times  by sea water. Therefore, the water of the temperature which is not considered exists in the ground of 200~400 ℃.
This is just a submarine wonder! A somewhat hotter bath is about 41 ℃. If it becomes, what heat is 400 ℃ hot water really? Isn't imagination attached, either? But such a thing has happened very ordinarily in deep sea.

　The chimney was discovered for the first time off the Galapagos Islands in 1977. Since then, a lot is discovered at a place which is called the boundary portion of a plate, etc. and where diastrophism is active. However, however the chimney might be discovered, the kind of living thing seen on the outskirts was generally the same. Even if it investigates the ocean of what, a kind does not change. How on earth were they scattered all over the world? Or did it carry out by producing a life one after another with the chimney? This mystery has not been solved yet. A chimney will surely be useful for research of primitive global environment.




reference

• http://www.nationalgeographic.co.jp/environment/habitats/deep-sea-vents.html
• http://rikanet2.jst.go.jp/contents/cp0170/main/stmain/contents/menu/menu.html
• http://ja.wikipedia.org/wiki/熱水噴出孔

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