On Earth, the oceans cover more than 70% of the Earth's surface, but humans have only explored 5% of the oceans. Obviously, compared with space, the ocean is an area that is easier for us to study closely, but so far, 12 astronauts have successfully landed on the moon, but only 3 manned submersibles can penetrate deep into the deepest part of the earth, reaching a depth of 10,900 meters in the Mariana Trench.
To explore the oceans freely, we must face the most common problems – water pressure and low temperatures, the deeper the water, the greater the pressure, which is difficult for humans to overcome. In 2006, explorer Gion Neri set a world record of 113 meters of freehand diving without any equipment. In 2014, an Egyptian diving enthusiast used scuba to dive to a depth of 332.35 meters underwater and could no longer go down, which shows that even in the case of equipment, the fragile human body cannot overcome the threat of water pressure. Diving at 332.35 meters is already the limit of the human body, but for the deep sea, a few hundred meters is only one percent.
The temperature of the ocean also varies greatly, it may be that the water temperature can drop to 0 ° C in a certain place, and in some special places, such as hydrothermal vents, the water temperature can soar to 400 ° C, in the ocean, the light can only travel to 200 meters underwater, and the ocean below 200 meters is almost dark and the visibility is extremely low. In addition, deep-sea divers face the threat of dangerous and unfamiliar marine life.
And the signal transmission in deep-sea exploration is also a big problem, to explore the universe, we often use radio waves, but not in the sea, radio waves in the water is not far away, and sonar This kind of equipment is limited, but also often affected by water temperature, salt, is reflected back, affected by the factors mentioned above, a deep-sea probe in the water, the field of vision is also very limited, may only see hundreds, thousands of square meters of range, but in the Earth orbit working Hubble telescope, But you can see the grand scene of space billions of light-years away.
Therefore, deep-sea exploration is an extremely challenging activity, requiring advanced equipment, adequate budgets, brave and experienced professionals, and the permission and support of the state and governments at all levels.
Modern scientific research suggests that the earliest life originated in the ocean. Scientists call the water in the primordial ocean "primitive soup", under the action of the sun's ultraviolet rays and lightning, the molecules in the "primitive soup" form organic macromolecules, and after hundreds of millions of years of evolution, these organic macromolecules "self-replication", began to evolve, and eventually formed life.
About 3.5 billion years ago, cyanobacteria, the most primitive and lowest prokaryotic organism, appeared in the primordial ocean, and since then, it has opened the prelude to the evolution of life on Earth. In short, after the gradual increase in water volume and salt, as well as the vicissitudes of geological history, the original ocean gradually evolved into today's ocean.
In this process, the ocean has accumulated rich mineral resources, it can be said that the ocean is a cornucopia of mineral resources, in 1873, the British marine survey ship first found deep-sea manganese nodules in the Atlantic Ocean, which is a recycled mineral, about 10 million tons per year at a rate of continuous growth, the total reserves of manganese nodules in the world's oceans that have been discovered are about 3 trillion tons, which contain manganese, copper, nickel and other minerals are tens or even thousands of times the land reserves. In addition, seabed oil, seabed placer ore, and seabed hydrothermal deposits are also important seabed resources. Once the technology matures, it is expected that deep-sea mining may become the norm in the 21st century.
In addition to this, there are various wonders in the magical ocean.
Many people think that the largest waterfall in the world is the Angel Waterfall in Venezuela, of course, this waterfall is indeed very large, its drop can reach 979.6 meters, but this can only be said to be the largest waterfall on the ground, the largest waterfall we know at present is actually in the sea, located in the Danish Strait between Greenland and Iceland Underwater Waterfall.
The waterfall begins 650 meters below the surface of the strait and then jumps 3,000 meters deep at the southern tip of Greenland, dropping nearly 2.5 kilometers in height. But that's not even the highest part, as it was detected to reach a maximum altitude of 3.5 kilometers, with as many as 5 billion liters of sea water pouring down from underwater cliffs every second, a volume equivalent to 25 times the flow of the Amazon River into the sea. The principle of underwater waterfall formation is also related to the drop difference and gravity.
In the sea, in simple terms, it is the confluence of ocean circulation, in the Danish Strait, the cold water flowing south in the Nordic Sea meets the warm water current in the Emminger Sea. Because of its density, the cold water flow quickly sinks under the warm water flow, and the warm water flow is squeezed and rises to the atmosphere to dissipate heat. In this ocean circulation convergence, the terrain with the height difference of the seabed is also used, resulting in spectacular underwater waterfalls.
Similar ocean wonders include the Ocean Blue Cave, which has a mysterious black hole in the universe, and there are also mysterious blue holes on Earth, and it can even be said that we know less about the blue hole than the black hole.
This is a very special marine landform, usually found on the coast or coral reef disc area, and is a cave covered by seawater, so named because it appears deeper than the surrounding blue water.
In 2012, Chinese fishermen found a blue hole near the Yongle Atoll in the South China Sea, scientists used a variety of detection equipment to determine that this is a depth of 300.89 meters, the deepest known ocean blue cave in the world, of which the deepest place may have been formed 25,000 years ago, but the specific causes, no one can say clearly, there is also the survival of microorganisms in the blue cave, as well as the lack of oxygen environment in the blue hole, are currently marine exploration is still studying the subject.
The earth has undergone countless changes in the earth's crust, volcanic eruptions, floods, glaciers and other changes, and some cultures and sites have submerged into the seabed after topographic changes or rising seawater, becoming mysterious underwater cities. Half a century ago, at the southern tip of Yonaguni Island in the Ryukyu Islands, people found that there was a ruins of an ancient city like an altar at a depth of 2600 meters, which contained various stone buildings, pillar caves, human head statues, stone tools and other objects, as well as surrounding market streets and farmland, and researchers also found uninterpretable, similar carvings.
Some scholars pointed out that the time when the land where this sea area is located was exposed to the ground was at least the last ice age 10,000 years ago, and people can't help but ask: Did the earth already have a prosperous and advanced ancient civilization 10,000 years ago? Will underwater ruins be a special case?
We may not be able to explain the doubts about the oceans yet, but it is precisely because of its richness that we have always been curious about it.
In 2020, the Strivers successfully dived more than 10,000 meters in the Mariana Trench to reach 10,058 meters, creating a new record for Manned Deep Diving in China, it is one of the three manned submersibles in the world that successfully reached the deepest part of the Mariana Trench, but unlike other manned submersible missions, Strivers I not only dived deeper than the original submersible, but also creatively established a call between the Mariana Trench and the ground, in the Mariana Trench, Strivers I collected a lot of deep sea material, such as seawater, Minerals, etc., which means we're taking another big step forward in deep-sea exploration.
Now, people explore outer space, outwardly mysterious milky way, but in the face of this ocean full of unknowns around us, we have not stopped wanting to explore the ideal. In the future, can we uncover more secrets about the ocean? See.