The Mariana Trench is the deepest place on our planet. This absolute depth got its name thanks to the nearby Mariana Islands. The entire depression stretches along the islands for one and a half thousand kilometers and has a characteristic V-shaped profile. In fact, this is an ordinary tectonic fault, the place where the Pacific Plate goes under the Philippine, just the Mariana Trench is the deepest place of its kind. Its slopes are steep, on average about 7-9 °, and the bottom is flat, 1 to 5 kilometers wide, and divided by rapids into several closed sections. The pressure at the bottom of the Mariana Trench reaches 108.6 MPa, which is more than 1100 times higher than normal atmospheric pressure!
The first who dared to challenge the abyss were the British - the military three-masted corvette "Challenger" with sailing equipment was rebuilt into an oceanographic vessel for hydrological, geological, chemical, biological and meteorological work back in 1872. But the first data on the depth of the Mariana Trench was obtained only in 1951 - according to the measurements carried out, the depth of the depression was declared equal to 10 863 m. After that, the deepest point of the Mariana Trench was called the “Challenger Deep”. It is hard to imagine that in the depths of the Mariana Trench the highest mountain on our planet - Everest - will easily fit, and more than a kilometer of water will remain above it to the surface.
The next researchers of the Mariana Trench were already Soviet scientists - in 1957, during the 25th voyage of the Soviet research vessel Vityaz, they not only declared the maximum depth of the depression equal to 11, 022 meters, but also established the presence of life at depths of more than 7, 000 meters, thereby refuting the then prevailing notion about the impossibility of life at depths of more than 6000-7000 meters.
On January 23, 1960, the first human dive was made to the bottom of the Mariana Trench. They are US Navy Lieutenant Don Walsh and researcher Jacques Picard.
During the dive, they were protected by armored, 127 millimeters thick, walls of the bathyscaphe called "Trieste". The bathyscaphe was named after the Italian city of Trieste, in which the main work on its creation was carried out. According to the instruments on board the Trieste, Walsh and Picard sank to a depth of 11, 521 meters, but later this figure was slightly corrected - 10, 918 meters.
The dive took about five, and the ascent took about three hours, the researchers stayed at the bottom for only 12 minutes. But even this time was enough for them to make a sensational discovery - at the bottom they found flat fish up to 30 cm in size, similar to a flounder.
In 2012, American filmmaker James Cameron rode the Deepsea Challenger to the bottom of the Mariana Trench. He reached a depth of 10 898 m
Studies in 1995 showed that the depth of the Mariana Trench is about 10, 920 meters, and the Japanese Kaik probe, launched into the Challenger Abyss on March 24, 1997, recorded a depth of 10, 911.4 meters.
The Mariana Trench has repeatedly frightened researchers with monsters lurking in its depths. For the first time the expedition of the American research vessel "Glomar Challenger" collided with the unknown. Some time after the start of the descent of the apparatus, the device registering sounds began to transmit to the surface some kind of metallic rattle, reminiscent of the sound of metal being sawn. At this time, some obscure shadows appeared on the monitor, similar to giant fairy dragons with several heads and tails. An hour later, scientists were worried that the unique equipment made in the NASA laboratory from beams of ultra-strong titanium-cobalt steel, having a spherical structure, the so-called “hedgehog” with a diameter of about 9 m, could remain in the abyss of the Mariana Trench forever - so it was decided to immediately raise apparatus on board the ship. The “hedgehog” was taken from the depths for more than eight hours and as soon as it appeared on the surface, it was immediately put on a special raft.
The TV camera and echo sounder were lifted to the deck of the Glomar Challenger. The researchers were horrified when they saw how deformed the strongest steel beams of the structure were, as for the 20-centimeter steel cable on which the hedgehog was lowered, the scientists were not mistaken in the nature of the sounds transmitted from the water abyss - the cable was half-sawn. Who tried to leave the device at depth and why - will forever remain a mystery. The details of this incident were published in 1996 by the New York Times.
Another encounter with the unexplained in the depths of the Mariana Trench happened with the German research apparatus "Highfish" with a crew on board. At a depth of 7 km, the vehicle suddenly stopped moving. To find out the cause of the problem, the hydronauts turned on the infrared camera. What they saw in the next few seconds seemed to them a collective hallucination: a huge prehistoric lizard, gripping its teeth into the bathyscaphe, tried to gnaw it like a nut. Recovering from the shock, the crew activated a device called an "electric cannon", and the monster, struck by a powerful discharge, disappeared into the abyss.
On May 31, 2009, the automatic submarine Nereus sank to the bottom of the Mariana Trench. According to measurements, it sank 10, 902 meters below sea level. At the bottom, Nereus filmed a video, took some photos and even collected sediment samples at the bottom. Thanks to modern technology, researchers managed to capture a few representatives of the Mariana Trench.