What is the lithosphere and what does it consist of? Geographical shells of the Earth: types and characteristics

Since childhood, I was drawn to new knowledge like a magnet. While all my friends at the first opportunity ran into the yard to ride a bike and kick a ball, I spent hours reading children's encyclopedias. In one of them I met the answer to the question, what is lithosphere. I will tell you about this now.

How the planet works and what is the lithosphere

Imagine a bouncing rubber ball. It is completely made of one substance - that is, it has a homogeneous structure.

Our planet inside is not at all homogeneous.

In the very center of the earth there is a dense red-hot core.
It is followed by mantle.
On the surface the planet, like a blanket, covers Earth's crust.

Part of the mantle layer together with the earth's crust form the lithosphere - the shell of our planet. We live on it, we walk and drive on it, we build houses and plant plants.

What are lithospheric plates

Lithosphere It's not a complete shell. Imagine now a rubber ball that has been cut and glued back together. Everyone large piece such a ball this is a lithospheric plate.

Plate boundaries are very arbitrary because they are constantly changing are shifting collide - in general, live an active and eventful life. Of course, by our standards, they do not move too fast - a couple of centimeters a year, well, a maximum of six. But on a global scale, it still leads to big changes.

Past of the lithosphere

Geologists are extremely interested in how the planet developed. They found out a funny pattern: with a certain frequency, everything continents come together merging into one after which they part again. Like a group of friends who met, sat down and ran away again on business.

Now the planet is in the stage of separation, which occurred after the single continent of Pangea was divided into pieces.

It is believed that they are all will gather into a single whole - Pangea Ultima- in 200 million years. Those who are afraid of flying on airplanes will be very happy about this - there will be no need to cross the oceans.

True, you have to prepare for the strong climate change. The British will have to store warm clothes - they will be thrown to the North Pole. The inhabitants of Siberia, on the other hand, can rejoice - life in the subtropics shines on them.

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For the first time about structure of our planet I, like everyone else, learned in the classroom geography However, I didn't have any interest in it. Indeed, the lesson is boring, and pulls outside to play football and all that. Things were quite different when I started reading Jules Verne's novel. "Journey to the Center of the Earth". I still remember my impressions of what I read.

Earth structure

infiltrate deep into Earth it is quite problematic for a person, so the study of the depths is carried out using seismic equipment. Like a number of planets included in earth group, The earth has a layered structure. Under bark situated mantle, and the central part is core, consisting of iron-nickel alloy. Each of the layers is significantly different in its structure and composition. During the existence of our planet, heavier rocks and substances went deeper under the influence of gravity, and lighter stayed on the surface. Radius- the distance from the surface to the center, is more than 6 thousand kilometers.

What is the lithosphere

This term was first applied in 1916 coda, and until the middle of the last century was synonym notion "Earth's crust". Later it was proved that lithosphere captures the upper layers robes to a depth of several tens of kilometers. In the building, they are distinguished as stable (fixed) areas, as well as movable (folded belts). The thickness of this layer is from 5 to 250 kilometers. Beneath the surface of the oceans lithosphere has minimal thickness, and the maximum is observed in mountainous areas. This layer is the only one accessible to humans. Depending on the location, under the continent or the ocean, the structure of the crust may vary. The largest area is the oceanic crust, while the continental crust is 40%, but has more complex structure. Science distinguishes three layers:

sedimentary;
granite;
basaltic.

These layers contain the most ancient rocks, some of which are up to 2 billion years.

Lava lake in Erta Ale crater

The thickness of the crust under the oceans is from 5 to 10 kilometers. The thinnest crust is observed in the central oceanic regions. In the oceanic crust, like the continental, there are 3 layers:

marine sediments;
average;
oceanic.

Nishinoshima Island. Formed in the Pacific Ocean after the eruption of an underwater volcano in 2013

mentioning oceanic crust, it is worth noting the deepest place in the world ocean - Mariana Trench located in the western part Pacific Ocean . Depth of depression over 11 kilometers. highest point lithosphere can be considered the highest mountain - Everest, whose height is 8848 meters above sea level. The most deep well, drilled in the thickness of the earth's crust, goes deep into 12262 meters. It is located on Kola Peninsula 10 kilometers west of the city Polar, what in Murmansk region.

Chomolungma, Everest, Sagarmatha - the highest peak of the Earth

As long as humanity has existed, so many disputes have been going on about what is the structure of the earth. Sometimes advanced completely crazy theories. Among the most striking is the theory of hollow earth, the theory about cellular cosmogony and the theory that icebergs emerge from the bowels of the earth which is completely unimaginable. In continuation of the theory of the hollow earth, there is an assumption about populated center, supposedly there people live :)

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I have always loved studying geography. As a child, I was interested in learning more about the Earth we walk on every day. Of course, when I realized that inside our planet is nuclear reactor, I was a little pleased. However, the structure of the globe is already very exciting. For example, the upper solid part of the earth's surface.

What is the lithosphere

The lithosphere (from Greek - "stone ball") is called the shell of the earth's surface, or rather its solid part. That is, the oceans, seas, and other bodies of water are not the lithosphere. However, the bottom of any water resource is also considered to be a hard shell. Because of this, the thickness of the hard crust fluctuates. In the seas and oceans, it is thinner. On land, especially where mountains rise, it is thicker.

What is the thickness of the solid part of the Earth

But the lithosphere has a limit, if you dig into the depths, then the next ball after the lithosphere is the mantle. In addition to the earth's crust, the upper and hard cover of the mantle also enters the lower part of the lithosphere. But deeper in the bowels of the globe, the second layer softens, becomes more plastic. These areas are the limit of the solid shell of the earth. The thickness ranges from 5 to 120 kilometers.

Time divided the lithosphere into parts

There is such a thing as a lithospheric plate. The entire solid shell of the Earth split into several dozen plates. They tend to move slowly due to the compliance of the soft part of the mantle. It is interesting that, as a rule, volcanic and seismic activity is formed at the junctions of these plates. These are the largest lithospheric plates of this size.

Pacific Plate - 103,000,000 km².
North American Plate - 75,900,000 km².
Eurasian plate - 67,800,000 km².
African Plate - 61,300,000 km².

Plates can be continental or oceanic. They differ in thickness, oceanic ones are much thinner.

This is what the part of the globe is where we walk, drive, sleep and exist. The more I learn about the structure of our planet, the more I am surprised and delighted by how everything is globally thought out and arranged.

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After leaving school, I considered surveying as one of the options for further education. In order to enter the engineering specialty, in addition to mathematics, geography was required, so I diligently prepared for the entrance exams. One of the topics that I remember well then was the structure of the Earth - this is a very interesting section that tells about the structure of our planet.

Earth's crust or lithosphere

Imagine an ordinary egg. It, like the Earth, has a hard shell (shell) on the outside, a liquid protein inside and in the very center - the yolk. It reminds me a little of the simplified structure of the Earth. But back to the lithosphere.

The solid shell of the planet is similar to eggshell because it is very thin and light. The Earth's crust is only 1% of the entire mass of the Earth and, unlike the shell, the lithosphere does not have an integral structure: the Earth's crust consists of plates drifting along the molten magma layer.

In one calendar year, the continents move by 7 cm.

This explains the frequent earthquakes and volcanic eruptions that affect territories located near the joints lithospheric plates.

The reason for the thinness of the lithosphere

To understand why the lithosphere took the form in which we know it, we need to turn to the history of the Earth.

4 billion years ago, an asteroid made of ice served as the basis for our planet. It revolved around the sun in a giant cloud space debris, which "stuck" to him.

Soon the Earth became massive and all of its weight began to press on the inner layers so hard that they melted.

Melting led to the following consequences:

water vapor rose to the surface;
gases came out of the bowels;
atmosphere has been formed.

Because of the Earth's gravity, steam and gases could not escape into space.

An incredible amount of water vapor appeared in the atmosphere, which collapsed from the clouds onto the boiling magma. Under the influence of precipitation, the magma cooled and petrified.

Newly minted pieces of the earth's crust collided with each other and were crushed - continents appeared, and water accumulated in places of depressions, which formed the World Ocean.

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In my understanding, the lithosphere is our habitat, our home, thanks to which the existence of all life is ensured. I think that The lithosphere is the most important resource potential of the Earth. Just imagine how many reserves of various minerals it contains!

What is the lithosphere from a scientific point of view

The lithosphere is a hard, but at the same time very fragile shell of our planet. Its outer part borders on the hydrosphere and atmosphere. It consists of the earth's crust and the upper part of the mantle.

The crust is divided into two types - oceanic and continental. Oceanic - young, it is relatively small in thickness. It oscillates constantly in the horizontal direction. The continental or, as it is also called, the continental layer is much thicker.

The structure of the earth's crust

Exist two major type plots bark: relatively fixed platforms and movable areas. Earthquakes and tsunamis are caused by plate movement. and other dangerous natural phenomena. The section of science studies these processes - tectonics. Due to the fact that I live in a relatively motionless central part European plain, I was lucky never in my life to see the destructive power of earthquakes with my own eyes.

Let's now go directly to the structure.

The continental crust consists of three main layers arranged in layers:

Sedimentary. Surface layer on which we walk. Its thickness reaches up to 20 km.
Granite. It is formed by igneous rocks. Its thickness is 10-40 km.
Basaltic. Massive layer of igneous origin 15-35 km thick.

What is the earth's crust made of

Surprisingly, the earth's crust, which seems to us so powerful and thick, consists of relatively light-weight substances. It includes about 90 different elements.

The composition of the sedimentary layer includes:

clay;
shales;
sandstones;
carbonates;
volcanic rocks;
coal.

Other elements:

oxygen (50% of the entire bark);
silicon (25%);
iron;
potassium;
calcium, etc.

As we can see, the lithosphere is a very complex structure. Not surprisingly, it has not yet been fully explored.

I've always been interested in getting to the bottom of things. Therefore, as a child, I absolutely could not understand how the ancient "literates" claimed that the earth stands on elephants, turtles and other living creatures, without verifying this fact. And after I saw pictures with seas flowing from the edge of the earth, I decided to thoroughly understand the issue of the structure of my native planet.

What is the lithosphere

This is the same “land” that was like a pancake located on the backs of three whales (in the view of the ancient “scientists”), that is solid shell of the planet. On it we build houses and grow crops, on its surface the oceans rage, mountains rise, and it shakes when an earthquake occurs. And although the word "shell" seems to be something solid and monolithic, but, nevertheless, The lithosphere consists of separate pieces - lithospheric plates, slowly drifting along the red-hot mantle.

Lithospheric plates

Like ice floes in a river lithospheric plates float, constantly colliding with each other or, on the contrary, parting in different sides . And it should be noted that the tiles are nothing like that, large ( 90% of the Earth's surface is made up of just 13 of these plates.).

The largest of them:

Pacific Plate - 103300000 square km;
North American - 75900000;
Eurasian - 67800000;
African - 61300000;
Antarctic - 60900000.

Naturally, when such colossus collide, it cannot but end in something grandiose. True, this will happen very, very slowly, since the speed of movement of lithospheric plates is from 1 to 6 cm/year.

If one plate rests against another and begins to slowly crawl onto it, or both do not want to yield,mountains are formed(sometimes very high). And in the place where one "crust" of the earth has gone down, a deep gutter can appear.

If the plates, on the contrary, quarreled and move away from each other - magma begins to flow into the gap formed, forming small ridges.

And it also happens that the plates do not collide and do not scatter, but simply rub against each other, like a cat on the leg.

Then a very deep long crack appears in the earth, and unfortunately strong earthquakes can occur, which is clearly demonstrated by the San Andreas fault in seismically unstable California.

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And any negative lithospheric changes can exacerbate the global crisis. From this article you will learn about what the lithosphere and lithospheric plates are.

Concept definition

The lithosphere is the outer hard shell of the globe, which consists of the earth's crust, part of the upper mantle, sedimentary and igneous rocks. It is rather difficult to determine its lower boundary, but it is generally accepted that the lithosphere ends with a sharp decrease in viscosity. rocks. The lithosphere occupies the entire surface of the planet. The thickness of its layer is not the same everywhere, it depends on the terrain: on the continents - 20-200 kilometers, and under the oceans - 10-100 km.

The Earth's lithosphere mostly consists of igneous igneous rocks (about 95%). These rocks are dominated by granitoids (on the continents) and basalts (under the oceans).

Some people think that the concepts "hydrosphere" / "lithosphere" mean the same thing. But this is far from true. The hydrosphere is a kind of water shell of the globe, and the lithosphere is solid.

Geological structure of the globe

The lithosphere as a concept also includes geological structure of our planet, therefore, in order to understand what the lithosphere is, it should be considered in detail. The upper part of the geological layer is called the earth's crust, its thickness varies from 25 to 60 kilometers on the continents, and from 5 to 15 kilometers in the oceans. The lower layer is called the mantle, separated from the earth's crust by the Mohorovichich section (where the density of matter changes dramatically).

Earth consists of the earth's crust, mantle and core. The earth's crust is a solid, but its density changes dramatically at the boundary with the mantle, that is, at the Mohorovichic line. Therefore, the density of the earth's crust is an unstable value, but the average density of a given layer of the lithosphere can be calculated, it equals 5.5223 grams / cm 3.

The globe is a dipole, that is, a magnet. Earth's magnetic poles are located in the southern and northern hemispheres.

Layers of the Earth's lithosphere

The lithosphere on the continents consists of three layers. And the answer to the question of what the lithosphere is will not be complete without considering them.

The upper layer is built from a wide variety of sedimentary rocks. The middle one is conditionally called granite, but it consists not only of granites. For example, under the oceans, the granite layer of the lithosphere is completely absent. The approximate density of the middle layer is 2.5-2.7 grams/cm 3 .

The lower layer is also conditionally called basalt. It consists of heavier rocks, its density, respectively, is greater - 3.1-3.3 grams / cm 3. The lower basalt layer is located under the oceans and continents.

The earth's crust is also classified. There are continental, oceanic and intermediate (transitional) types of the earth's crust.

The structure of lithospheric plates

The lithosphere itself is not homogeneous, it consists of peculiar blocks, which are called lithospheric plates. They include both oceanic and continental crust. Although there is a case that can be considered an exception. The Pacific lithospheric plate consists only of oceanic crust. The lithospheric blocks consist of folded metamorphic and igneous rocks.

Each continent has at its base an ancient platform, the boundaries of which are defined by mountain ranges. Plains and only individual mountain ranges are located directly on the platform area.

Seismic and volcanic activity is quite often observed at the boundaries of lithospheric plates. There are three types of lithospheric boundaries: transform, convergent, and divergent. The outlines and boundaries of lithospheric plates change quite often. Small lithospheric plates are connected to each other, while large ones, on the contrary, break apart.

List of lithospheric plates

It is customary to distinguish 13 main lithospheric plates:

Philippine plate.
Australian.
Eurasian.
Somali.
South American.
Hindustan.
African.
Antarctic Plate.
Nazca plate.
Pacific;
North American.
Scotia plate.
Arabian plate.
Cooker Coconut.

So, we gave a definition of the concept of "lithosphere", considered the geological structure of the Earth and lithospheric plates. With the help of this information, it is now possible to answer with certainty the question of what the lithosphere is.

Lithosphere of the Earth in literal translation means "stone shell". This is one of the shells of the planet, formed by solid components. Consider what the lithosphere consists of and the proportion of which the planet needs it.

What it is?

The planet's lithosphere is the layer that covers it, formed top mantle and earth's crust. Such a definition was given in 1916 by the scientist Burrell. It is located on a softer layer - the asthenosphere. The lithosphere covers the entire planet completely. The thickness of the upper hard shell is not the same different areas. On land, the thickness of the shell is 20-200 km, in the oceans - 10-100 km. An interesting fact is the presence of a Mohorović surface. This is a conditional boundary separating layers with different seismic activity. Here there is an increase in the density of the substance of the lithosphere. This surface completely repeats the earth's relief.

Rice. 1. The structure of the lithosphere

What is the lithosphere formed by?

The development of the lithosphere has been going on since the formation of the planet. The solid earth shell is formed mainly by igneous and sedimentary rocks. In the course of various studies, the approximate composition of the lithosphere was established:

oxygen;
silicon;
aluminum;
iron;
calcium;
trace elements.

The outer layer of the lithosphere is called the earth's crust. This is a relatively thin shell, having a thickness of no more than 80 km. The greatest thickness is noted in the mountainous regions, the smallest - in the plains. The composition of the earth's crust on the continents includes three layers - sedimentary, granite and basalt. In the oceans, the crust is formed by two layers - sedimentary and basalt, the granite layer is absent.

Many planets have crust, but only the Earth has differences between oceanic and continental crust.

Under the crust is the main part of the lithosphere. It consists of separate blocks - lithospheric plates. These plates slowly move along a softer shell - the asthenosphere. The processes of plate movement are studied by the science of tectonics.

How do plates move?

The regularities of the lithosphere also include features of the movement of lithospheric plates. They constantly change their outlines, but this happens so slowly that a person is not able to notice it. It is assumed that 200 million years ago there was only one continent on the planet - Pangea. Due to some internal processes there was a separation of it into separate continents, the boundaries of which pass through the places of the split of the earth's crust. A sign of plate movement today can serve as a gradual warming of the climate.

Since the movement of lithospheric plates does not stop, some scientists suggest that in a few million years the continents will again unite into one continent.

What natural phenomena are associated with the movement of plates? In the places of their collision, the boundaries of seismic activity pass - when the plates hit each other, an earthquake begins, and if this happened in the ocean, then a tsunami.

The movements of the lithosphere are also responsible for the formation of the planet's topography. The collision of lithospheric plates leads to crushing of the earth's crust, resulting in the formation of mountains. Underwater ridges appear in the ocean, and deep-sea trenches appear at the places where the plates diverge. The relief also changes under the influence of the air and water shells of the planet - the hydrosphere and atmosphere.

Rice. 3. Due to the movement of lithospheric plates, mountains are formed

Ecological situation

One example of the connection between the biosphere and the lithosphere is the active influence of human actions on the shell of the planet. The rapidly developing industry leads to the fact that the lithosphere is completely polluted. Chemical and radiation waste, pesticides, hardly decomposable garbage are buried in the soil. The influence of human activity has a noticeable effect on the relief.

What have we learned?

We learned what the lithosphere is and how it was formed. We found out that the lithosphere consists of several layers, and its thickness is not the same in different parts of the planet. The components of the lithosphere are various metals and trace elements. The movement of lithospheric plates causes earthquakes and tsunamis. On the state of the lithosphere big influence has an anthropogenic impact.

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It is called the crust and enters the lithosphere, which is translated from Greek literally means "stony" or "hard ball". It also includes part of the upper mantle. All this is located directly above the asthenosphere ("powerless ball") - above a more viscous or plastic layer, as if underlying the lithosphere.

Earth's internal structure

Our planet has the shape of an ellipsoid, or more precisely, a geoid, which is a three-dimensional geometric body of a closed shape. This most important geodesic concept is literally translated as "similar to the Earth." This is what our planet looks like from the outside. Internally, it is arranged as follows - the Earth consists of layers separated by boundaries that have their own specific names (the clearest of them is the Mohorovichic boundary, or Moho, separates the crust and mantle). The core, which is the center of our planet, the shell (or mantle) and the crust - the upper solid shell of the Earth - these are the main layers, two of which - the core and the mantle, in turn, are divided into 2 sublayers - inner and outer, or lower and upper. Thus, the core, whose sphere radius is 3.5 thousand kilometers, consists of a solid inner core (radius 1.3) and a liquid outer one. And the mantle, or silicate shell, is divided into lower and upper parts, which together account for 67% of the total mass of our planet.

The thinnest layer of the planet

The soils themselves arose simultaneously with life on Earth and are the product of the impact environment- water, air, living organisms and plants. Depending on the various conditions(geological, geographical and climatic) this most important natural resource has a thickness of 15 cm to 3 m. The value of some types of soil is very high. For example, during the occupation, the Germans exported Ukrainian black earth in rolls to Germany. Speaking of earth's crust, one cannot but mention large solid areas sliding over more liquid layers of the mantle and moving relative to each other. Their rapprochement and "arrivals" threaten tectonic shifts, which can be the cause of disasters on Earth.

The core, mantle and crust are internal structure Earth. What is the lithosphere? This is the name of the outer solid inorganic shell of our planet. It includes the entire earth's crust and the upper part of the mantle.

In a simplified form, the lithosphere is the upper layer consisting of three layers. In the scientific world there is no unambiguous definition of the concept of this planetary shell. And the debate about its composition is still ongoing. But according to the available information, it is still possible to draw up basic ideas about what the lithosphere is.

Structure, composition and boundaries

Despite the fact that the lithosphere covers absolutely the entire earth's surface and upper layer mantle, in weight equivalent, this is expressed in only one percent of total weight our planet. Although the shell has small volumes, its detailed study raised a lot of questions, and not only about what the lithosphere is, but also what material it is formed from, what state it is in in different parts.

The main part of the shell is hard rocks, which at the boundary with the mantle acquire a plastic consistency. In the structure of the earth's crust, stable platforms and folding areas are distinguished.

Different thicknesses and can range from 25 to 200 kilometers. On the ocean floor, it is thinner - from 5 to 100 kilometers. The Earth's lithosphere is limited by other shells: the hydrosphere (water) and the atmosphere (air).

The earth's crust is composed of three layers:

sedimentary;
granite;
basalt.

Thus, if you look at what the lithosphere is in a section, it will resemble a layer cake. Its basis is basalt, and on top it is covered with a sedimentary layer. Between them, in the form of a filling, there is granite.

The sedimentary layer on the continents was formed as a result of the destruction and modification of granite and basalt. On the ocean floor, such a layer is formed as a result of the accumulation of sedimentary rocks carried by rivers from the continents.

The granite layer consists of metamorphic and igneous rocks. On the continents, it occupies an intermediate position between other layers, and at the bottom of the oceans, it is completely absent. It is believed that in the very "heart" of the planet there is basalt, consisting of igneous rocks.

The earth's crust is not a monolith, it consists of separate blocks, called which are in constant motion. They seem to float on the plastic asthenosphere.

During its existence, mankind in economic activity constantly used the constituent parts of the lithosphere. The earth's crust contains everything that is widely used by people, and their extraction from the bowels is constantly increasing.

The soil is of great value - the preservation of the fertile layer of the lithosphere today is one of the most urgently needed solutions.

Some processes occurring within the boundaries of the shell, such as erosion, landslides, mudflows, can be caused by anthropogenic activities and pose a threat. They not only influence the formation of ecological situations in certain territories, but can also lead to global environmental cataclysms.