What is the inner structure of the globe?

The Earth is part of the solar system along with the rest of the planets and the Sun. It belongs to the class of hard stone planets, characterized by a high density and consisting of rocks, in contrast to gas giants that are large and relatively low in density. In this case, the composition of the planet determines the internal structure of the globe.

The main parameters of the planet

Before you know what layers are allocated in the structure of the globe, let's talk about the main parameters of our planet. The Earth is at a distance from the Sun, approximately equal to 150 million km. The nearest heavenly body is the natural satellite of the planet - the Moon, which is located at a distance of 384 thousand km. The Earth-Moon system is considered unique, as it is the only one where the planet has such a large satellite.

The Earth's mass is 5.98 x 10 ²⁷ kg, the approximate volume is 1.083 x 10 ²⁷ cu. See The planet revolves around the Sun, as well as around its own axis, and it tilts relative to the plane that determines the seasons. The period of revolution around the axis is approximately 24 hours, around the Sun - just over 365 days.

Mysteries of the internal structure

Before the method of exploring the depths with the help of seismic waves was invented, scientists could only make assumptions about how the Earth is arranged inside. Over time, they developed a number of geophysical methods that allowed us to learn about some features of the structure of the planet. In particular, seismic waves are widely used, which are fixed as a result of earthquakes and earth crust movements. In some cases, such waves are generated artificially, in order to familiarize themselves with the situation at depth by the nature of their reflections.

It is worth noting that this method allows you to receive data indirectly, since there is no way to directly get into the depths of the bowels. As a result, it was found that the planet consists of several layers, differing in temperature, composition and pressure. So, what is the inner structure of the globe?

Earth's crust

The upper solid shell of the planet is called the Earth's crust. Its thickness varies from 5 to 90 km, depending on the type, which is 4. The average density of this layer is 2.7 g / cm3. The largest capacity is of the continental crust, the thickness of which reaches 90 km under some mountain systems. Also distinguish the oceanic crust located under the ocean, the thickness of which reaches 10 km, transitional and rifting. Transitional differs in that it is located on the boundary of the continental and oceanic crust. Riftogenic cortex occurs where there are mid-oceanic ridges, and differs by a small thickness, which reaches only 2 km.

Bark of any type consists of rocks of 3 types - sedimentary, granite and basaltic, which differ in density, chemical composition and nature of origin.

The lower boundary of the cortex is called the Moho boundary, in honor of its discoverer named Mohorovicic. It separates the cortex from the underlying layer and is characterized by a sharp change in the phase state of the substance.

Mantle

This layer follows the solid crust and is the largest - its volume is approximately 83% of the total volume of the planet. The mantle begins immediately after the Moho boundary and extends to a depth of 2,900 km. This layer is additionally divided into upper, middle and lower mantle. A feature of the upper layer is the presence of the asthenosphere - a special layer, where the substance is in a state of low hardness. The presence of this viscous layer explains the movement of the continents. In addition, during the eruption of volcanoes, the liquid molten substance poured out by them comes precisely from this region. The upper mantle ends at a depth of about 900 km, where the average begins.

Distinctive features of this layer include high temperatures and pressure, which increase with increasing depth. This determines the special state of the substance of the mantle. Despite the fact that in the depths of the rock have a high temperature, they are in a solid state due to the action of high pressure.

Processes taking place in the mantle

The bowels of the planet have a very high temperature, due to the fact that the thermonuclear reaction process is continuously occurring in the nucleus. However, conditions are comfortable on the surface. This is possible due to the presence of a mantle, which has heat-insulating properties. Thus, the heat released by the nucleus enters it. The heated substance rises upwards, gradually cooling, while the cooler matter is plunged down from the upper layers of the mantle. This cycle is called convection, it occurs non-stop.

The structure of the globe: the core (external)

The central part of the planet is a nucleus, which begins at a depth of about 2900 km, immediately after the mantle. In this case, it is clearly divided into 2 layers - external and internal. The thickness of the outer layer is 2200 km.

The characteristic features of the outer core layer are the predominance in the composition of iron and nickel, in contrast to the compounds of iron and silicon, of which the mantle mainly consists. The substance in the outer core is in a liquid aggregate state. Rotation of the planet causes the motion of the liquid substance of the nucleus, because of which a powerful magnetic field is formed. Therefore, the outer core of the planet can be called the generator of the magnetic field of the planet, which deflects dangerous types of cosmic radiation, so that life on Earth's surface was born.

Internal core

Inside the liquid metal shell is a solid inner core, whose diameter reaches 2,5 thousand km. At present, it is still not properly studied, but there are disputes between scientists regarding the processes taking place in it. This is due to the difficulty of obtaining data and the possibility of using only indirect research methods.

It is known for certain that the temperature of the substance in the inner core is not less than 6 thousand degrees, however, despite this, it is in a solid state. This is due to the very high pressure that does not allow the substance to go into a liquid state - in the inner core it is supposedly equal to 3 million atm. Under such conditions, a special state of matter may arise-metallization, when even elements such as gases can acquire the properties of metals and become solid and dense.

As far as the chemical composition is concerned, there are still disputes in the research environment about what elements constitute the inner core. Some scientists suggest that the main components are iron and nickel, others - that among the components can be also sulfur, silicon, oxygen.

The ratio of elements in different layers

Earth composition is very diverse - it contains almost all elements of the periodic system, but their content in different layers is not uniform. Thus, the earth's crust has the lowest density, therefore it consists of the lightest elements. The heaviest elements are in the core in the center of the planet, at high temperature and pressure, providing the process of nuclear decay. Such a relationship was formed within a certain time - immediately after the formation of the planet its composition was supposedly more homogeneous.

In the lessons of geography, students can suggest drawing a structure of the globe. To cope with this task, you need to adhere to a certain sequence of layers (it is described in the article). If the sequence is broken, or one of the layers is missing, then the work will be done incorrectly. Also, the sequence of the layers can be seen in the photo presented to your attention in the article.