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Why does the Red Sea expand?
1978165438+1October 14, Kaba volcano in Adu, North America suddenly erupted, with thick smoke billowing and a large amount of lava overflowing. A week later, it was found that the distance between Arabian Peninsula and distant African continent increased by 1 m, that is to say, the Red Sea expanded by 1 m in seven days.

The Red Sea is a strange ocean. It not only expands slowly, but also the water temperature in several places is extremely high, exceeding 50℃. The seabed of the Red Sea is rich in high-grade metal deposits. These phenomena have not been scientifically explained for a long time, which is called the mystery of the Red Sea.

The mystery of the Red Sea began in the 1960s. Marine geologists explained that the mystery of the Red Sea lies in a series of "hot holes" on the seabed. After a detailed investigation of the seabed around the world, scientists found that the seabed has mountains and deep valleys like land, which are undulating. On the topographic map of the seabed, we can see that there is a huge mountain system with a length of more than 75,000 kilometers and a width of more than 960 kilometers that runs through the global ocean. Scientists call this submarine mountain system "mid-ocean ridge", and the long and narrow Red Sea is being crossed by the mid-ocean ridge. Along the top of the mid-ocean ridge, there is also a longitudinal fault zone. The width of the rift valley is about13 ~ 48km, and the narrow one is 900 ~1200m. Scientists also found through hydrological measurements that the temperature of seawater near the middle of the rift valley is particularly high, as if there is a stove burning below, which is vividly called a "hot hole". Scientists believe that it is the mantle material pouring out from the hot caves that heats the seawater, produces mineral deposits and pushes the seabed to expand to both sides.

From 65438 to 0974, France and the United States began to jointly implement the mid-ocean underwater research program. The first goal of the plan is to visit the rift zone in the middle of the Atlantic Ocean at the southwest of Azores 124 km, which is similar to the bottom of the Red Sea.

The scientists in the submersible moved into the rift valley along the mid-ocean ridge and saw with their own eyes that the rift valley was slowly opening next to the "hot hole" spewing hot magma. The water temperature around the "hot hole" is particularly high. American geologist Bart put the diving temperature detector in the hot water fountain near the "hot hole". The pointer on the indicator in the submersible exceeded the maximum scale of 650 degrees Fahrenheit, and the thermometer melted because of the overrange. Afterwards, it was confirmed that the water temperature reached about Fahrenheit 1000 degrees.

Due to the high temperature of the seawater around the "hot hole", a unique seabed landform has been formed. Under normal circumstances, after the magma is ejected, it will quickly condense when it meets the cold sea water, forming a bulbous peach-shaped basalt block, while the magma ejected near the "hot hole" rotates, spirals and slowly cools in the overheated sea water, forming a special submarine lava slurry.

Chocron, a French geologist, made a detailed investigation on the process of submarine stretching and fracturing. He vividly compared the expansion of the seabed to a piece of soft candy with elongated ends. Where it is pulled thinner and thinner, the middle becomes a low-lying area and finally breaks, and magma is ejected from there, pushing the seabed to both sides. The bottom of the sea is slowly expanding. According to the measurement of Gemini spacecraft in the United States, we already know that the expansion rate of the Red Sea is 2 cm per year.

The exploration of the seabed by marine scientists not only solved the mystery of the expansion of the Red Sea, but also accidentally discovered strange biological communities near the submarine rift and "chimneys" spewing black mineral "smoke".

People used to think that life on earth was supported by sunlight. With sunlight, plants can grow, and with plants, plants can feed animals, even carnivores. 1977 In February, when scientists took the submersible Alvin near the underwater rift valley of the Galapagos Islands in the Pacific Ocean, they found a unique ecosystem that did not depend on sunlight at a depth where there was almost no life. In some areas of the seabed, the water temperature is surprisingly high, and giant shellfish, worms, crabs and other creatures gather here, forming an "oasis". Unfortunately, because biologists did not participate in this expedition, the research work did not go deep.

1978, scientists from France, the United States and Mexico found dead giant clams in some dormant underwater fountains in the eastern Pacific Rift Zone at the mouth of California Bay at 2 1 degree north latitude. These giant clams are almost the same as those found in the Galapagos region in 1977. The new findings show that the existence of underwater biological communities is related to the hot fountains on the seabed. Once the hot fountain stops spraying, the oasis on the seabed will disappear.

1979, scientists returned to the Galapagos Islands and found a dazzling picture of the biological community on the seabed: red-billed worms grew around the hot spring vents, blind short-jawed crabs crawled nearby, and the seabed was inhabited by extremely huge brown clams and mussels, and anemones bloomed like flowers. Strange dandelion-shaped foraminifera tied themselves near the fountain with silk. The most striking thing is those white plastic-like tubes, which are 2 ~ 3 meters long and from which blood-red bugs protrude.

Scientists have studied unusual worms. These bugs have no eyes, no intestines and no anus. Anatomy shows that these worms reproduce sexually, probably by dispersing eggs and sperm in water for fertilization. They rely on more than 300,000 tentacles to absorb oxygen and tiny food particles in the water.

Scientists are particularly interested in the biological oxidation and growth rate of the fountain mouth. Radiochemical experiments show that the Meretrix meretrix near the nozzle grows 4 cm a year, which is 500 times faster than that of the deep-sea Meretrix which can live for a hundred years. These bugs and clams are surprisingly red. Their red color is caused by hemoglobin, and their hemoglobin has an extraordinary affinity for oxygen, which may be an adaptability to the anoxic conditions in the deep sea.

Biologists believe that the miracle of the deep-sea oasis is caused by the hot springs in the submarine rift. Hot springs raise the water temperature nearby to 12 ~ 17℃. Under the high pressure and warm seabed, the sulfate in the fountain will become hydrogen sulfide. This smelly compound may be the energy source of metabolism of some bacteria. Bacteria multiply rapidly at the fountain mouth, reaching 1 cubic centimeter, 1 million. A large number of bacteria have become life-sustaining nutrients for worms and even clams. The suspended food in the fountain mouth is four times more than that in the bait-rich water meter. In this way, energy from the earth's interior maintains a special biological chain. Scientists call this degree "chemical synthesis".

Scientists have discovered five such oases on the seabed, which is 2500 meters deep near the underwater rift of Galapagos. The rift valley in the world's oceans is more than 75,000 kilometers long, including many hot springs. How many oases will there be? Will there be more biological communities? These problems are not only related to the exploitation of the ocean by human beings, but also related to the study of the basic theoretical topic of the origin of life.

Seawater contains many chemical elements, including 106 elements, and more than 80 elements can be found in seawater. There are also rich mineral deposits under the sea floor. It is generally believed that the elements and minerals in the ocean come from land and flow into the sea with rivers.

However, scientists have found that the content of elements in seawater is unbalanced. Compared with land, the proportion of manganese is too high and magnesium is insufficient. The investigation of the seabed also found that many mineral deposit elements are the most near the mid-ocean ridge and gradually decrease to both sides, which shows that the elements in the sea are not only from land.

Barit, an American geologist, found that there were 3-7 meters high submarine chimneys emitting black smoke near the submarine hot springs. "Smoke" is actually a high-heat solution containing high-concentration minerals, and the "chimney" itself is also formed by the cold precipitation of ejected minerals after encountering seawater. This discovery unveiled the mystery of the composition of seawater. Scientists put forward the view that the hot springs at the bottom of the deep sea bring out the minerals deep in the earth, but the seawater will also penetrate into the earth along the cracks. It is estimated that seawater circulates in the earth's crust every1000 ~ 20 million years. Heatwave metal deposits on the seabed, including copper, tin, silver, cobalt, zinc and sulfur. Many of the most valuable mineral deposits on the earth are caused by these hot springs carrying metals, and the enrichment of metal deposits on the seabed of the Red Sea is a typical example. Direct sampling from the water in the hot spring nozzle also proves that during the internal circulation of the oceanic crust, seawater loses part of magnesium and increases manganese.

According to the theory of evolution, human beings first evolved from protozoa in the ocean. Now humans are going to the ocean to learn about the ocean again. The depths of the ocean are basically an unknown kingdom for people today. Going to the deep sea is not much easier than going to the moon. In order to go deep into this unknown kingdom, you need to prepare for months at a time, but you can only stay there for a few hours. The success of the preliminary investigation aroused people's stronger curiosity. People can't help asking, what new and bigger secrets are there in the depths of the ocean waiting for us to discover?