The total area of the ocean is as high as 360 million square kilometers, accounting for 71% of the Earth's surface area. However, only 5% of the oceans are currently detected by humans, and the remaining 95% are still unexplored.
Fossil studies have found that the ancestors of vertebrates landed on land more than 300 million years ago. Later, except for a limited number of animals returning to the sea, none of them ever returned home. Over time, the former marine homeland has become a mysterious and dangerous field today.
Do you know? If the inner density of the seawater is large and the density of the lower layer is small, forming a "negative density" gradient jump layer, the buoyancy of the seawater will be sharply reduced from top to bottom, forming a terrible "seabed cliff".
Scientific probes concluded that the pressure of the liquid was proportional to its depth. The "deepest part" of the currently known ocean is located in the Mariana Trench, which can reach a depth of 11,000 meters, with a bottom pressure equal to about 1078 standard atmospheres, and 1 standard atmospheric pressure equal to 101325 Pascal. What is this concept? To put it bluntly, it's the equivalent of 270,000 adults pressing down on you at the same time.
Since World War II, the submarines of various navies have had several incidents of "undersea cliffs and deaths". On April 10, 1963, the U.S. Navy's 4,000-ton "Longtail Shark" attack nuclear submarine was unfortunately in distress, and was eventually torn into 6 sections and fell into the bottom of the sea at a depth of 2300 meters, killing 129 American troops on board.
In 1968, the Israeli submarine "Dakar", which had been mysteriously missing for 30 years in the Mediterranean Sea, was also speculated to have accidentally fallen into the "seabed cliff" of the jump layer and sank.
Two famous explorers from Switzerland, who once took a homemade submarine, dived to the bottom of the sea at a depth of 10811 meters, and after successfully landing ashore, the two unbelievably recalled: the pressure on the seabed is far beyond our imagination, our submarine uses the most compressive material, the outer layer is special tempered glass, but in the process of diving, they are easily broken.
Modern naval submarines have two layers of shells inside and outside, and many people may not know that the "pressure-resistant" shell inside is the key to directly determining the "diving depth" of the submarine. Submarines with "ultra-high strength steel" are usually used to create pressure-resistant shells with a maximum diving depth of 300-600 meters.
Only the Soviet Union has the courage to use pressure resistance on the third generation of the Navy's nuclear submarine "Komsomol", but the welding difficulty is extremely high, the cost is very expensive "titanium alloy" as a raw material for the pressure shell, and the submarine's diving depth ranks first in the world for more than 1,000 kilometers.
However, there are exceptions to everything, and in the face of the deadly cliffs under the sea, Chinese soldiers have created a "miracle in the history of the world's submarines".
That is, on the eve of the Spring Festival in 2014, the 372 submarine of our navy suddenly fell into the cliff of the seabed during the diving voyage to the predetermined sea, and after discovering that the submarine began to fall deep, in just 3 minutes, the officers and men of the whole boat, at the time of life and death, were not in danger, operated dozens of instruments, closed nearly a hundred valves and switches, and made no mistakes.
With the usual crisis training and the care of the god of fate, the 372 submarine miraculously succeeded in escaping from the cliffs under the sea after 14 minutes of darkness. After this matter was exposed, it immediately shocked the navies of all countries around the world.
Epilogue:
Many times, we will not only sigh, no matter how strong the power of man is, it is insignificant in the face of nature. Volcanoes, earthquakes, typhoons and other disturbances on the surface of small earths are all disasters for human beings. It is said that "man will triumph over heaven", and many people may not know that its original intention is that human beings themselves settle down and overcome the blessings of heaven, not to toss and turn.