What is the inside of the earth like

The earth is a huge sphere. The research results show that the earth can be divided into several concentric circles. Looking roughly, it can be roughly divided into three circles: crustal, mantle (also known as "middle layer").

The crust is a hard shell outside the earth. The crust is composed of various rocks. Except for a thin layer of sedimentary rocks, weathering soil and sea water, the upper part is mainly composed of granite -like rocks, while the lower part is mainly composed of basalt or long rocky rocks. The average thickness of the crust is 33 kilometers, but the place is not the same. Generally, the mainland is thicker than the ocean and the mountains are thicker than the plain. The thickness of the crust in the mainland is generally 35 kilometers, but the ocean region is only 5-10 kilometers. The crustal thickness of Tibet in my country is 60-80 kilometers, and the eastern plain is more than 30 kilometers. The density of the crust is between 2.6-3g/cm3; the pressure increases from top to bottom from one atmospheric pressure to 1300 atmospheric pressure; the temperature is increased to about 1000 ° C.

The mantle is between the crust and the nucleus and can be divided into two layers. The upper layer (that is, the upper mantle) is 33-900 kilometers from the ground. In addition to the silicon and oxygen of the material components, the iron and magnesium are significantly increased, and the aluminum is retired. The pressure is 500,000 atmospheric pressure, the temperature is 1200-1500 ° C, and the material state is solid crystal, but it has a large plasticity. The lower layer (that is, the lower mantle) is 900-2900 kilometers from the ground. In addition to the silicon, the metal oxide and sulfide are significantly increased, especially the average density of 5.6g/cm3, and the pressure is 1.5 million. Atmospheric pressure, the temperature is 1500-2000 ° C, the material state is a non-crystalline state. The volume of the mantle accounts for 83%of the total volume of the earth, and the mass accounts for 66%of the entire earth. Due to the results of high temperature and high pressure, mantle substances are often in the lava state and become the birthplace of magma.

The core refers to the core part of the mantle to the earth. The pressure of the center of the earth can reach 3.5 million atmospheric pressure, and the temperature is about 3000-5000 ° C. Under such high temperature and high pressure, the material in the center of the earth cannot be represented by the words "solid" or "liquid" we are familiar with. It is a material state that people are not familiar with. This material is characterized by the long -term effect of high temperature and high pressure, as plasticity like resin and wax; but for a short time, it is harder than steel. However, the scientific community has different arguments about the composition of the nuclear nuclear, which needs to be further studied and explored.

Author: Yao Wang

Source: Shaanxi Science and Technology News

- END -