The earth s crust is how many meters is the 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 relatively thick, with an average thickness of about 35 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.

The earth's crust is divided into two layers, upper and lower. The chemical composition of the upper layer is mainly oxygen, silicon, and aluminum, and the average chemical composition is similar to that of granite, which is called granite layer, and some people also call it "silicon-aluminum layer". This layer is thin at the bottom of the ocean, especially in the ocean basin floor, and even absent in the central Pacific Ocean, and is an uncontinuous circle.

The lower layer is rich in silicon and magnesium, and the average chemical composition is similar to that of basalt, which is called the basalt layer, so some people call it the "silicon-magnesium layer" (another way of saying that the entire crust is a silicon-aluminum layer, because the aluminum content of the lower layer of the earth's crust still exceeds that of magnesium; The rock part in the upper part of the mantle has a very high magnesium content, so it is called a silicon-magnesium layer); It is distributed in both continents and oceans, and is a continuous circle. The two floors are separated by a Conrad discontinuity.

The Earth's crust is the outermost layer of the Earth's solid sphere and an important part of the lithosphere. Its bottom bound is the Moholovich discontinuity (Moho surface). The average thickness of the earth's crust is about 17 km, of which the continental crust is larger, with an average of 33 km.

The crust in high mountains and plateaus is thicker, 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.

The average thickness of the crust is about 17 km, and the thickness of the continental crust is larger, with an average of 33 km

Alpine and highland areas.

The degree of Houling sedan can reach 60-70 kilometers;

The oceanic crust is thin, with an average thickness of about 6km

The interior of the earth has a layered structure of concentric spherical layers, and the material composition and physical properties of each layer change. The interior of the earth cannot be directly observed, so most knowledge about the interior of the earth is obtained indirectly. For example, the average density of the Earth can be calculated to be 3

However, the density of surface material is less than g cm3 ; Therefore, it can be inferred that the density of the material in the Earth's interior is greater than that of gram cm3. According to the fact that meteorites are divided into stony meteorites and iron meteorites, and because the earth has an obvious endogenous magnetic field, it can be inferred that there is an iron core inside the earth. Mainly according to the various signs shown by the propagation of ** waves in the earth's interior, it is proved that the earth's interior can be roughly divided into 3 components: the crust, the mantle and the core.

Earth's crust The outermost layer of the Earth's spherical structure. The thickness of the crust of the Otomo is generally 35 45 km, and the thickness of the crust in the Himalayas can reach 70 80 km. 1909 a

Moholovich confirmed the existence of the subcrustal interface based on the travel time of the near-seismic wave, and the velocity of the longitudinal wave below this interface suddenly increased from an average of kilometers to kilometers. This sub-interface was later called the Moho interface. The continental crust is generally divided into the upper crust and the lower crust, the upper crust is harder, which is the main stress and prone to the occurrence of ** layer, and the lower crust is softer

The oceanic crust is thinner, generally with only one layer, and is more uniform than the continental crust.

Mantle The middle layer between the earth's crust and core. The average thickness is more than 2,800 kilometers. 1914, B

Gutenberg measured the depth of the interface between the Earth's core and the mantle at 2,900 km, which is quite accurate and is only 15 km short of the newly calculated value. The Earth's mantle is further divided into the upper mantle (above 350 km depth) and the lower mantle. There is a low-velocity layer of ** waves in the upper mantle, and the low-velocity layer is above the relatively hard top of the upper mantle.

The top of the upper mantle and the earth's crust are often referred to as the lithosphere. The global lithospheric plates make up the outermost structure of the earth, and the tectonic movement of the earth's surface is mainly carried out within the lithosphere.

The study of crustal equilibrium suggests that there is a layer of material beneath the lithosphere, which is less strong and allows for slow deformation and horizontal flow. 1914, JBalrell calls this layer of matter the asthenosphere.

The asthenosphere concept and the concept of the low-velocity layer of the mantle in **science seem to refer to the same object, and many people associate them with the same thing. The theory of plate tectonics holds that lithospheric plates float above the asthenosphere and can move horizontally on a large scale.

The core of the Earth, mainly composed of iron and nickel, has a radius of 3,480 kilometers1936 , iAccording to the longitudinal wave passing through the earth's core, Lyman proposed that there is a sub-interface in the earth's core, and the earth's core is divided into two parts: the outer core and the inner core.

Since the field nucleus cannot detect the hole for the transverse wave to pass through, it is inferred that the material state of the field core is liquid.

The composition of the earth's crust is divided into two layers, namely:

The chemical composition of the upper layer is mainly oxygen, silicon, and aluminum, and the average chemical composition is similar to that of granite, which is called granite layer, and some people also call it "silicon-aluminum layer".

The lower layer is rich in silicon and magnesium, and the average chemical composition is similar to that of basalt, which is called the basalt layer, so some people call it the "silicon-magnesium layer".

The earth's crust (qiào) is a solid shell composed of rocks, the outermost layer of the earth's solid sphere, an important part of the lithosphere, and the interface between the earth's crust and the mantle is a Moholovich discontinuity (Moho surface).

Soil and rocks, the chemical composition is mainly silicate.

The primordial earth is a homogeneous solid, which has just cooled down from its red-hot state. However, "the trees want to be quiet and the wind does not stop", and the cooling earth is facing a moment of melting. The heat that causes the Earth to melt again comes mainly from microstars falling from the sky.

The gravitational pull of huge planets is often very strong, attracting tiny stars roaming in the solar system, and the story of big fish eating small fish is staged. Dust and debris are attracted by the earth and hit the surface of the earth, and the kinetic energy is converted into heat energy, which causes the surface temperature of the earth to rise. At the same time, due to the overall contraction of the earth, the density of the earth's interior is increasing, and the pressure is also increasing, resulting in an increase in the temperature of the earth's interior.

And some radioactive elements contained in the earth itself, such as uranium, emit heat when decaying, accumulate for a long time, and the energy is also considerable.

Three streams of heat surged through the Earth's body, melting the newly solidified Earth again, reaching a temperature of 1000 or more. At 400 to 800 kilometers underground, the temperature even exceeds the melting point of iron. Metals such as iron and nickel in solid rocks are the first to melt, and due to the high density of these elements, under the action of gravity, iron and nickel form molten droplets, which sink to the center of the earth, and finally form a core of iron and nickel in the center of the earth. Lighter rocky materials, such as silicon, aluminum, magnesium, etc., float up to the surface and cool to form the earth's crust.

The material between the earth's crust and core forms the mantle.

The loss of heat has once again frozen the earth, at least on the surface, under a world of solid rock. Is the earth getting hotter or colder? We know that the greenhouse effect warms the planet due to the increase in carbon dioxide in the atmosphere.

However, when people talk about global warming, they mainly refer to the earth's atmosphere. For the earth as a whole, especially the solid spheres, although there are no more microstars in the sky and the earth no longer shrinks, the decay of radioactive elements is long-term, from the day of the earth's birth to today. It has been calculated that the current loss of geothermal energy from the Earth's interior will reduce the Earth's temperature by 100 percent in 1 billion years; The accumulation of thermal energy generated by the decay of radioactive elements can raise the Earth's temperature by 200 percent in 1 billion years.

Simply doing the offset calculation, the temperature in the Earth's interior should be increasing. The ancients had "people worried about the sky", afraid that the sky would fall; Today, we don't have to worry about the earth melting. Because the temperature rises extremely slowly, every 1 rise takes tens of millions of years.

Moreover, the thermal conductivity of the earth's rocks is very poor, and it takes a long time for the heat to reach the surface. For now, it's more realistic to deal with the greenhouse effect first.

The earth was born without a crust, because it was much closer to the sun than it is now, the whole earth was irradiated by the sun's high heat rays and was in a molten state, and later due to the centrifugal force generated by the revolution around the sun, the earth gradually cooled down and began to solidify, plus various alien objects landed on the surface of the earth and gradually evolved into the current crust.

It is precisely because the earth's crust is formed in this way that it can be understood that the earth's crust is floating on the mantle, and there are various crustal movements now.

About 4.5 billion years ago, some gases, dust, ice particles and other materials gathered together to gradually form the prototype of the earth, which is only 1 kilometer in size, which is very small compared to the vast universe. But it is this "little earth" that keeps rotating, absorbing and accumulating other materials around it, and after tens of millions of years of accumulation, it has gradually formed the size of the current earth.

When the earth was first formed, it was always hit by various meteorites and asteroids in the universe, and the radioactive elements inside the earth generated a lot of heat, so the ground at that time was full of erupting volcanoes and flowing lava, and the earth was basically a big fireball covered with lava. When the number of asteroids hitting the Earth decreased, the temperature on the Earth's surface decreased, and the magma slowly solidified and agglomerate, forming a cratered primitive crust.

The formation of the primitive crust (from left to right: magma everywhere - magma gradually cooling - potholed primitive crust).

This is how the earth's crust is formed.

The above content refers to Milley's children's book "A Brief History of Life".

A brief history of natural life in the universe, your popular science primer丨Produced by scientific sound, it must be a high-quality product.

Jiang Fashi's theory of crustal motion is that there are many factors that form the movement of the earth's crust, and his views are as follows:

First of all, we should know what crustal movement is, and then classify crustal movement, different types of crustal movement have different causes.

Crustal motion is a mechanical movement that refers to the change in position of the earth's crust and its constituent substances relative to a certain reference. There are n references, so there are n kinds of crustal movements. Just choose those references that make sense as the ones for the movement of the earth's crust.

Different types of crustal movement have different causes and different movement mechanisms, resulting in different movement results.

According to the reference, there are six types of crustal movements:

1. Crustal movement with the silver surface as the reference; 2. Crustal motion with the ecliptic plane as a reference; 3. Crustal movement with the earth's axis as a reference; 4. Crustal movement with geographical coordinates as a reference; 5. Crustal movement with surface objects as references; 6. Crustal motion with spherical surface as a reference.

As for the theory of crustal motion, according to the factors that cause crustal motion, it is divided into two categories: single-cause crustal motion and multi-cause crustal motion.

The traditional theories of crustal motion belong to the theory of crustal motion due to single causes, such as continental drift, seafloor expansion, plate theory, geomechanics, depression theory, fault block theory, mosaic theory, multi-cycle theory, etc. The above six classifications belong to the theory of multi-cause crustal motion, which was proposed by Jiang Fashi in China.