What do we know about the deepest place in the World Ocean? This is the Mariana Trench or the Mariana Trench.
What is its depth? This is not an easy question …
… but definitely not 14 kilometers!
In the section, the Mariana Trench has a characteristic V-shaped profile with very steep slopes. The bottom is flat, several tens of kilometers wide, divided by ridges into several almost closed sections. The pressure at the bottom of the Mariana Trench is more than 1100 times higher than normal atmospheric pressure, reaching 3150 kg / cm2. Temperatures at the bottom of the Mariana Trench (Mariana Trench) are surprisingly high due to hydrothermal vents, nicknamed "black smokers". They constantly heat the water and keep the overall temperature in the basin at about 3 ° C.
The first attempt to measure the depth of the Mariana Trench (Mariana Trench) was made in 1875 by the crew of the English oceanographic vessel Challenger during a scientific expedition to the World Ocean. The British discovered the Mariana Trench quite by accident, during a routine bottom measurement using a lot (Italian hemp rope and lead weight). For all the inaccuracy of such a measurement, the result was amazing: 8367 m. In 1877, a map was published in Germany, on which this place was marked as the Challenger Abyss.
The measurement, made in 1899 from the board of the American coal miner "Nero", showed a great depth: 9636 m.
In 1951, the bottom of the depression was measured by the British survey vessel “Challenger”, named after its predecessor, informally called “Challenger II”. Now, with the help of the echo sounder, a depth of 10899 m was recorded.
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The maximum depth indicator was obtained in 1957 by the Soviet research vessel "Vityaz": 11,034 ± 50 m. It is strange that no one remembered the anniversary date of the epoch-making discovery of Russian oceanologists. However, they say that when taking readings, the change in environmental conditions at different depths was not taken into account. This erroneous figure is still present on many physical and geographical maps published in the USSR and Russia.
In 1959, the American research vessel "Stranger" measured the depth of the trench in a rather unusual way for science - using depth charges. Result: 10915 m.
The last known measurements were made in 2010 by the American vessel "Sumner", they showed a depth of 10994 ± 40 m.
It has not yet been possible to obtain absolutely accurate readings even with the most modern equipment. The operation of the echo sounder is hampered by the fact that the speed of sound in water depends on its properties, which manifest themselves differently depending on the depth.
This is how the most durable hulls of underwater vehicles look after tests at extreme pressure. Photo: Sergey Ptichkin / RG.
And now it is reported that Russia has developed an autonomous unmanned underwater vehicle (AUV) capable of operating at a depth of 14 kilometers. Hence the conclusion is drawn that our military oceanologists have found a depression in the World Ocean deeper than the Mariana.
The announcement that the device was created and passed its test compression at a pressure corresponding to a depth of 14,000 meters was made during an ordinary press trip of journalists to one of the leading scientific centers involved in, among other things, deep-sea vehicles. It’s even strange that no one paid attention to this sensation and has not yet voiced it. And the developers themselves did not become too frank. Or maybe they just reinsure themselves and want to get reinforced concrete evidence? And now we have every reason to expect a new scientific sensation.
It was decided to create an uninhabited deep-sea vehicle capable of withstanding pressure that is much higher than that exists in the Mariana Trench. The device is ready for use. If the depth is confirmed, it will become a super sensation. If not, the device will work to the maximum in the same Mariana Trench, study it up and down. In addition, the developers claim that with a not very complicated revision, the AUV can be made habitable. And it will be comparable to manned deep space missions.
The existence of the Mariana Trench has been known for a long time, and there are technical possibilities for descending to the bottom, but over the past 60 years, only three people have been able to do this: a scientist, a military man and a film director.
For the entire time of the study of the Mariana Trench (Mariana Trench), devices with people on board were lowered to its bottom twice and automatic devices four times (as of April 2017). By the way, fewer than people visited the moon.
On January 23, 1960, the Trieste bathyscaphe sank to the bottom of the Mariana Trench (Mariana Trench). On board were the Swiss oceanographer Jacques Picard (1922-2008) and the US Navy lieutenant, explorer Don Walsh (born 1931). The bathyscaphe was designed by Jacques Picard's father, a physicist, inventor of the stratospheric balloon and bathyscaphe Auguste Piccard (1884-1962).
In a black and white photograph half a century ago, - legendary bathyscaphe "Trieste" in preparation for the dive. The crew of two was in a spherical steel gondola. It was attached to a float filled with gasoline to provide positive buoyancy.
The descent of "Trieste" lasted 4 hours 48 minutes, the crew periodically interrupted it. Plexiglass glass cracked at a depth of 9 km, but the descent continued until the Trieste sank to the bottom, where the crew saw a 30-centimeter flat fish and some crustacean creature. Having spent about 20 minutes at a depth of 10,912 m, the crew began the ascent, which took 3 hours 15 minutes.
Another attempt to descend to the bottom of the Mariana Trench (Mariana Trench) was made in 2012, when American filmmaker James Cameron (born 1954) became the third to reach the bottom of the Challenger Abyss. Earlier, he repeatedly dived on Russian Mir spacecraft into the Atlantic Ocean to a depth of over 4 km during the filming of the movie Titanic. Now, on the Dipsy Challenger bathyscaphe, he sank into the abyss in 2 hours 37 minutes - almost a widow faster than the Trieste - and spent 2 hours 36 minutes at a depth of 10898 m. After that, he rose to the surface in just an hour and a half. At the bottom, Cameron saw only creatures that looked like shrimps.
The fauna and flora of the Mariana Trench are poorly studied.
In the 1950s. Soviet scientists during the expedition of the ship "Vityaz" discovered life at depths of more than 7 thousand meters. Before that it was believed that there was nothing living there. Pogonophores were discovered - a new family of marine invertebrates living in chitinous tubes. Disputes about their scientific classification are still ongoing.
The main inhabitants of the Mariana Trench (Mariana Trench), living at the very bottom, are barophilic (developing only at high pressure) bacteria, the simplest creatures of the foraminifera - unicellular in shells and xenophiophores - amoebas, reaching 20 cm in diameter and living by shoveling silt.
Foraminifera managed to get the Japanese automatic deep-sea probe "Kaiko" in 1995, which sank to 10911.4 m and took soil samples.
Larger inhabitants of the gutter live throughout its entire thickness. Deep life made them either blind or with highly developed eyes, often telescopic. Many have photophores - organs of luminescence, a kind of bait for prey: in some, on long processes, like in an angler fish, while in others it is in the mouth right away. Some accumulate a luminous liquid and, in case of danger, douse the enemy with it in the manner of a "light curtain".
Since 2009, the basin has been part of the American Conservation Area Mariana Trench National Marine Monument with an area of 246,608 km2. The zone includes only the underwater part of the trough and the water area. The reason for this action was the fact that the Northern Mariana Islands and the island of Guam - in fact, American territory - are the island boundaries of the water area. The Challenger Abyss is not included in this zone, as it is located in the oceanic territory of the Federated States of Micronesia.