At 9: 22 on June 17, Beijing time, the Long March II F- 12 carrier rocket carrying the Shenzhou 12 manned spacecraft was ignited and lifted off. Since then, the Shenzhou-12 manned spacecraft has successfully separated from the rocket and entered the scheduled orbit, successfully sending three astronauts into space. The pilot was in good condition and the launch was a complete success.

How high did Shenzhou XII fly?

After a flight of about 585 seconds, the Chang 'e II F rocket will send the Shenzhou-12 spacecraft into an elliptical orbit 200 kilometers away from the Earth and 393 kilometers away from the Earth.

What about the focal depth when the earthquake happened?

Shallow earthquakes, whose focal depth is less than 70km, accounts for more than 90% of the global earthquakes. At present, the deepest focal depth is 720 kilometers.

Difficulties in earthquake prediction

0 1

Complexity of seismogenic process (mechanism difficulty)

02

Inaccessibility of deep source (technical difficulty)

03

The probability of strong earthquake events is small (it is difficult to practice and accumulate scientifically)

Why is it more difficult to "get into the ground"?

At present, "underground" exploration mainly relies on scientific drilling, using mechanical engineering technology of deep geological drilling to exploit underground and seabed natural resources, or taking stratigraphic profiles, extracting physical samples, providing experiments and obtaining relevant data.

Scientific drilling helps us to know more about the causes of geological activities; Contribute to the development and utilization of resources and energy, such as investigating and developing deep heat energy; In environmental science, it is helpful to study the causes of earthquakes, the mechanism of volcanic eruption and the early warning of geological disasters.

Since 1970s, many developed countries have successively implemented some scientific drilling plans, which are represented by:

Kola peninsula drilling in the Soviet Union12262m is ultra-deep, which is the deepest well in the world at present. Germany KTB- ultrasonic deep drilling, the depth is 9 10 1 m, ranking second; Well No.2 in Song Ke, China is 70 18m deep.

We know that the diameter of the earth is 12756 km, and the deepest hole drilled by humans is 12262 m. In this way, man's understanding of the interior of the earth is only a scratch. So, why is it so difficult to "get into the ground"?

However, this technology also has limitations, which is why humans have been unable to drill deeper for so many years.

All this should be discussed from the particularity of the earth's underground.

We are talking about the interior of the earth from the surface of Gutenberg to the center of the earth, which we call the core. The core is the core of the earth, mainly composed of iron and nickel, with a radius of 3,480 kilometers, a total mass of 3 1.5% and a volume of 16.2% of the whole earth.

There are many reasons why you can't drill deeper. First, the pressure is great. In the outer core, the pressure reached 6.5438+0.36 million atmospheres, and in the core, it increased to 3.6 million atmospheres, making it impossible to drill. Second, the temperature is high, and the internal temperature of the core can reach between 4000 and 8000. The drill bit is far from being able to withstand such high temperature. Third, the density is high. The average density of the core material is about 65,438+00.7 g/cm3, which is impenetrable by the hardest drill.

Wang Dandan Tang Peiliang Editor

Layout: Wang Dandan, Wang Yuan