The closest place to the Moho interface is on the seabed. According to the data of geologists, the average thickness of the crust in marine areas is 7 kilometers thinner than that on land. That is to say, drilling on the seabed is more labor-saving than drilling on land, and the soil on the seabed is still soft, and seawater can cool the drill bit.
After the location was determined, the Moho project officially began soon. However, the plan cannot keep up with the changes. During the first drilling, many basalts were found in the marine crust, which brought great trouble to drilling and doubled the capital. Therefore, at 1966, the plan was terminated early due to high funds.
At that time, the Soviets also wanted to dig underground with tools. 1970, the Soviet union called a group of top geologists and drillers to kola peninsula, which was the most suitable place for deep-hole drilling in the Soviet union at that time.
At the beginning of the project, researchers took it for granted that the work was not difficult, as long as the rotating machinery was connected with the long rod-shaped drill pipe, and then the drill bit kept drilling and digging, and several people ensured the stable operation of the power rotating machinery. However, when I really started to do it, I found that the pit was too big.
The actual situation at that time was that the corresponding rock pressure, hardness and temperature would increase every time the drilling dropped100m. At that time, the cost of drill bits used by Soviet scientists was tens of thousands of dollars, but in actual drilling, a drill bit would break before it was drilled deep. Therefore, scientists at that time temporarily invented a special triangular awl drill.
At that time, many accidents occurred during drilling. One of the more serious problems is that when the drilling rig drilled to a depth of 7 kilometers, the steel pipe broke and remained in the borehole. It took the staff seven months to take out the broken steel pipe. When the broken steel pipe was taken out, it also meant that all the drilling achievements in the past five years were in vain.
SG-3 is the deepest drilling in recent ten years, and it is also the deepest drilling in the world so far. This drilling took 13 years, and the total drilling depth was12000m, of which the last 262m was 10 years.
In fact, according to the actual situation at that time, if we really want to dig through the crust of 17000 meters, it will take at least one hundred years, and the money spent in this hundred years is astronomical. In the end, the drilling in Kola of the Soviet Union failed to penetrate the earth's crust. By 1993, the Kola drilling project was officially closed, and by 2008, this place was completely abandoned.
Of course, there are still rich scientific discoveries in the drilling process, which has spent so much manpower and material resources. First of all, through this drilling, we know that there are a lot of water resources in the earth's crust. It is generally believed that granite is very dry, but all the excavated materials are hot mineralized water. Secondly, at a depth of more than 3000 meters, some multicellular organisms have been discovered, which is the deepest biological existence ever discovered by human beings. At the same time, at a depth of 6700 meters, microbial fossils 2 million years ago were also found; Deep in the boiling mud, scientists also found a lot of hydrogen.
At a depth of nearly 10000 meters, scientists also discovered a geological layer with extremely high gold content. The value of this gold mine far exceeds the value standard of commercial mining by 20 times! The online rumor that a monster crawled out of the hole is a lie. You know, at that time, the diameter of the bottom of the borehole was only 20 cm, the internal temperature was as high as 300 degrees Celsius, and the pressure was 1000 times atmospheric pressure. Do you think life is possible?
Nowadays, this1.2m deep pit is visited by more and more people. Although some people have proposed to continue digging, according to relevant research, digging through the soil is not beneficial, and there are many complex geological structures under the thick rock layer, which will lead to a series of geological disasters if you are not careful. As for what is inside the earth, human science needs to go further.