June 12, 2013. Scientists sometimes joke that the depth of the oceans are less well than the reverse side of the moon. This is quite a truthful statement, to date, according to various sources, the oceans studied only by 2-5%.
At the bottom of the oceans, there are real underwater river, or rather, the cases of so-called "cold seepage." It is referred to as sites where hydrogen sulfide, methane and other hydrocarbons seep through cracks at the bottom mixed with the sea water, and then slowly moving, like rivers. The word "cold" in the title of this phenomenon does not mean that the liquid in the bottom of rivers has a temperature lower than the surrounding seawater.
In addition to underwater rivers, the ocean, there are also underwater waterfalls. And some of them are much more of their land, "relatives." Total to date, there are seven of these waterfalls. The reason for their occurrence are differences in temperature and salinity of the different parts of the ocean and the complex topography of the seabed. On the boundary waters with different conditions and in the presence of underwater slopes dense water tends to the bottom — to replace the less dense water.
Sometimes appear in the ocean "milk sea". This "sea" is a vast luminous portion of the ocean. And despite the fact that there are a lot of pictures of this phenomenon, how it arises, scientists do not know exactly. According to one version, the "sea of milk" appears because of the luminescent bacteria Vibrio harveyi, which create a lasting glow in large parts of the ocean.
According to a study published in 2011 in the journal PLOS Biology, the ocean is home to about 2.2 million species of organisms, of which we know only about 194,400 species.
The biggest fish that lives in the oceans — the whale shark. Some individuals of this species had a length of 12.65 meters and reach a weight of 21.5 tons. Today, whale sharks live in tropical and warm temperate seas. But the largest inhabitant of the ocean, of course, the blue whale. Its length is 33 meters, and the weight of the animal may exceed 150 tonnes. At the same time, the smallest fish in the oceans is Schindleria brevipinguis, inhabit the coral barrier reef lagoons. Fish of this kind can only reach 8.4 mm in length.
There are cases when the ocean was formed a "false bottom". First learned about it in 1942, when several experts on acoustic sensing found in the ocean at a depth of 300-450 meters countries reflecting the sound waves fat. And later, it was found that at night this unknown layer rose to the surface of the sea, and in the afternoon — went down into the depths. That's when it became clear that the "false bottom" may be formed by living organisms that avoid daylight. There was a set of assumptions, what kind of organisms created a "false bottom". But in the end it turned out that it did squid. After all, in packs they can be applied uniformly, and thus able to form a solid mass, which can be a barrier to sound.