The division of the Earth s inner sphere, and what is the basis for the division of the Earth s inne

Physical geography - the sphere structure of the earth.

The inner sphere is divided into the crust, mantle and core from the outside to the inside. The interface between the crust and the mantle is the Moho interface, and the interface between the mantle and the core is the Gutenberg interface.

1. Earth's crust. The earth's crust is the outermost layer of the earth's solid surface structure, with an average thickness of about 17 kilometers, of which the continental crust is larger, with an average thickness of about 39-41 kilometers. The crust is thicker in the mountains and plateaus, up to 70 km; Plains and basins have relatively thin crusts.

The oceanic crust is much thinner than the continental crust, only a few kilometers thick.

2. Moho noodles.

In 1910, Mohorovich proposed that the earth has an inner and outer layer. The inner and outer layers he refers to are what we call the mantle and crust. The interface between the Earth's crust and the mantle is also known as the Moholovich discontinuity (Moholovich surface).

On the Moho surface, the propagation velocity of the longitudinal and transverse waves of ** waves increases significantly, the elasticity and density gradually increase with depth, and the density and hardness of mantle materials are greater than those of the crust. The average chemical composition of the materials above this surface is similar to that of basalt, and the density is about; The average chemical composition of the following substances on this surface is similar to that of peridotite, and the density is about that. The temperature of the moho surface is 400-1000

3. Mantle. The mantle is between the Moho surface and the Gutenberg surface, with a thickness of more than 2800 km, and the average density is about the volume of the earth, and the mass of the mantle accounts for about the total mass of the earth, which greatly affects the total composition of the earth's material. The transverse variation of the mantle is relatively uniform, and according to the change of wave velocity in **, the 1000 km surge zone is used as the interface (Ray Poti surface), and two sub-layers of the upper mantle and the lower mantle are further divided.

4. Gutenberg interface.

Gutenberg Interface, aka Gutenberg Interface. It is divided according to the change of wave velocity and is the interface between the mantle and the core. In addition to a significant change in wave velocity at a depth of about 33 km in the Earth's interior (here called the Moho interface, which is the boundary between the earth's crust and mantle), at a depth of about 2900 km, the wave propagation state also changes significantly, which is called the Gutenberg interface.

The mantle is located between the Moho interface and the Gutenberg interface.

Since the outer core of the Earth is liquid, the ** wave in the mantle (the S wave is a transverse wave, and the transverse wave can only propagate in solids) cannot travel through this interface in the outer core. The velocity of the p-wave (longitudinal wave) curve also decreases sharply at this interface.

5. The Earth's core. The Earth's core is the core part of the Earth and is located in the innermost part of the Earth. The radius is about 3470 km, mainly composed of iron and nickel elements, and the density is high, and the average density of the earth's core material is about grams per cubic centimeter.

The temperature is very high, there are 4000 to 6800.

Physical geography - the sphere structure of the earth.

The Earth's interior cannot be directly observed. Geoscientists use the most advanced methods to study the structure and composition of the Earth's interior. According to geophysical research, the interior of the earth is a heterogeneous body, and there are obvious differences in the density, pressure, temperature, physical state and chemical composition of each layer of matter.

There are two distinct wave discontinuities in the Earth's interior, which divides the Earth's interior into three concentric spheres: the crust, the mantle, and the core (Fig. 5-3-3). The crust and the top of the mantle are made up of hard rock, about 70 km to 150 km thick, also known as the lithosphere.

1) The earth's crust is a thin layer of crust on the earth's surface. The thickness is uneven, the average thickness in the mainland is about 35 kilometers, and the thickest part can reach 70 kilometers (such as the Qinghai-Tibet Plateau in China); The average ocean area is about 7 km, only 4 km at its thinnest point, the volume of the earth's crust is 1% of the volume of the whole earth, the mass is 0 4 of the global mass, and the density is 1 2 of the average density of the earth, which is 2 7 2 9 g cm3. The extremely harmful shallow sources of the continent** occur in this layer of the earth's crust.

2) Mantle: The mantle is between the earth's crust and core.

In the upper part of the upper mantle, at an average depth of 60 250 km below the Earth's surface, there is an asthenosphere, which lies below the lithosphere and is a low-velocity layer of pronounced ** waves, with a flexible substance. The asthenosphere may be closely related to many activities on the Earth's surface, it is the source of magma, the source of ** and volcanic phenomena, causing mantle convection, seafloor spreading, and plate tectonics, forming useful mineral deposits.

3) The core of the earth refers to the core part of the earth, with a radius of about 3400 kilometers, the mass and volume of 31 5 and 16 of the world respectively, the density is extremely high, the edge area is 9 7 grams of centimeters3, the center of the core is 13 grams of height 3, the temperature also rises with depth, the temperature of the edge of the core of the earth is 3700, and the center of the earth reaches 5500-6000. The Earth's core is mainly composed of high-density iron-nickel alloys. The Earth's core is also divided into two parts: the outer core and the inner core.

The inner sphere of the earth is divided into three layers, and the following is how to divide the inner sphere of the earth.

01 The inner circle of the earth is divided into three circles, which are called the crust, mantle and core from the outside to the inside. Both the earth's crust and the mantle above the asthenosphere are made of relatively hard rocks, also known as the lithosphere.

02 Earth's crust.

Because there are mountains, plains, and rivers on the earth, the thickness of the earth's crust is different, the crust on the continent is thicker, and the oceanic crust is thinner, and the average thickness of the entire crust is about 17 kilometers.

03 Mantle.

The mantle is between the earth's crust and the earth's core, also known as the mesosphere. From below the earth's crust to a depth of 2,900 kilometers, there is the mantle layer, which is divided into three layers: the upper mantle, the transition zone and the lower mantle.

04 Core.

Below the mantle to the center of the earth is the core layer, about 5,100 kilometers, which divides the core into an outer core and a core, and the core is hot and stressful.

The internal structure of the earth refers to the layered structure of the earth's interior. According to the change in the propagation velocity of ** waves at different depths underground, the interior of the earth is generally divided into three concentric spheres: the core, the mantle and the crust.

The central layer is the core; In the middle is the mantle; The outer layer is the earth's crust. The crust and mantle are bounded by the Moho plane, and the mantle is bounded by the Gutenberg surface between the earth's core. The characteristics of the various spheres of the Earth's interior.

1. The outer core of the earth's core is liquid or molten, and the core is iron-nickel solid. The Earth has not just one core, but two, the inner core and the outer core. The reason why the Earth's core is solid is because the pressure created by gravity here is the pressure on the Earth's surface'3,000,000 times.

The Earth's core can reach a high temperature of 13,000 degrees Fahrenheit, which is 2,000 degrees higher than the surface temperature of the sun. The iron flow in the Earth's core causes the matter to create a huge magnetic field that can protect the Earth from foreign rays.

2. The mantle is an iron-magnesium solid, and the asthenosphere in the upper part of the mantle is the source of magma.

3. The thickness of the earth's crust is uneven, the continental crust is thick and the oceanic crust is thin, the crust is a silicon-aluminum layer, and the lower is a silicon-magnesium layer.