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• Structure of the Earth
• The structure of the lithosphere and phenomena in it:

• What is the lithosphere?
• Rocks that make up the earth's crust;
• Movements of the earth's crust:
• a) Earthquakes;
• b) Volcanism;
• c) Hot springs and geysers
• The main forms of relief of the Earth's surface:
• Mountains and plains of land;
• Mountains and ocean plains.

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Structure of the Earth

Currently, scientists assume that there is a core in the center of the Earth, its radius is about 3500 km. The core is surrounded by a mantle, its thickness is approximately 2900 km. Above the mantle is the earth's crust, its thickness ranges from 5 to 80 km. The earth's crust is the hardest shell. The mantle substance is in a special plastic state; this substance can flow slowly under pressure. The heaviest and densest substances are found in the core; the temperature there is about 3500°.

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What is the lithosphere?

The earth's crust consists of three layers: sedimentary, granite, basalt. Each layer of the earth's crust is remarkable in its own way.

Sedimentary rocks were formed by the deposition of matter on land or its deposition in an aquatic environment. They lie in layers replacing each other. Behind the sedimentary rocks is a layer of granite. Granite was formed as a result of the eruption and solidification of magma in the earth's crust under conditions of high temperatures and pressure. This is an igneous rock. The next layer of the earth's crust after granite is basalt. Basalt is also of igneous origin. It is heavier than granite and contains more iron, magnesium and calcium. The earth's crust is not the same thickness everywhere. The thickness of the earth's crust is less under the oceans than under the continents. The greatest thickness of the earth's crust is observed under mountain ranges.

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Rocks that make up the earth's crust

The earth's crust is composed of a wide variety of minerals and rocks. In these layers you can find deposits of minerals - coal, oil, rock salt. All these minerals are of organic origin. Granite was formed as a result of the eruption and solidification of magma in the earth's crust under conditions of high temperatures and pressure. This is an igneous rock. Basalt is heavier than granite and contains more iron, magnesium and calcium.

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Movements of the earth's crust

Scientists believe that the earth's crust is divided by deep faults into blocks or plates of different sizes. These plates move through the liquefied mantle layer relative to each other. There are plates that contain only the crust of the continents (the Eurasian plate). But most plates contain both the crust of the continents and the crust of the ocean floors. In places where plates converge, they collide, one plate moves onto another, and mountain belts, deep-sea trenches, and island arcs are formed. Vivid examples of such formations are the Japanese and Kuril Islands. Scientists associate the movement of plates with the movement of matter in the mantle. What forces move lithospheric plates? These are the internal forces of the Earth, resulting from the decay of radioactive elements that make up the Earth's core.

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Video “Movement of the Earth’s Crust. Mountain building"

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The boundaries of lithospheric plates are located both in places of their rupture and in places of collision - these are moving areas of the earth's crust, to which most active volcanoes are confined and where earthquakes are frequent. These areas form the Earth's seismic belts. The Earth's seismic belts include areas of the Pacific coast, the Mediterranean, and the Atlantic coast. The largest seismic belt on Earth is the Pacific Volcanic Belt, or, as it is often called, the Pacific “Ring of Fire.”

The more we move away from the boundaries of the moving sections towards the center of the plate, the more stable sections of the earth's crust become. Moscow, for example, is located in the center of the Eurasian plate, and its territory is considered quite seismically stable.

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EARTHQUAKES

The displacement of some sections of the earth's crust relative to others in the horizontal and vertical directions at great depths in the lithosphere is called an EARTHQUAKE.

The place at depth where a rupture and displacement of rocks is formed is called an EARTHQUAKE FOCUS.

The place on the earth's surface located above the source is called the EARTHQUAKE EPICENTER.

The most severe destruction occurs at the epicenter, where tremors are directed from bottom to top.

Seismological scientists have compiled a scale to measure the strength of an earthquake in points from 1 to 12.

The consequence of earthquakes in the oceans is TSUNAMI.

Slide 12

VOLCANISM

VOLCANO (from Latin “vulcanus” - fire, flame), a geological formation that appears above channels and cracks in the earth’s crust, through which lava, ash, hot gases, water vapor and rock fragments erupt onto the earth’s surface. There are active, dormant and extinct volcanoes, and in shape they are central, erupting from a central channel and fissures, the vents of which look like gaping cracks or a series of small cones. The main parts of a volcano are the magma chamber (in the earth's crust or upper mantle); vent - an outlet channel through which magma rises to the surface; cone - a rise on the surface of the Earth from the products of a volcanic ejection; crater - a depression on the surface of a volcano cone. Modern volcanoes are located along large faults and tectonically mobile areas (mainly on islands and shores of the Pacific and Atlantic Ocean). Active active volcanoes: Klyuchevskaya Sopka and Avachinskaya Sopka (Kamchatka, Russian Federation), Vesuvius (Italy), Izalco (El Salvador), Mauna Loa (Hawaiian Islands), etc.

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Volcanoes

Video of Mount Etna, Sicily

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Volcano in Hawaii

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HOT SPRINGS AND GEYSERS

In areas where there are volcanoes, groundwater has a high temperature and contains various salts and gases in dissolved form, i.e. are mineral. These waters flow to the surface, forming springs, streams, and rivers. Sometimes they burst out like a hot fountain, rising to a height of several tens of meters. Such gushing sources are called GEYSERS.

People use hot underground waters to heat rooms and greenhouses (Kamchatka, Iceland). Mineral springs are for medicinal purposes.

Slide 17

BASIC RELIEF FORMS OF THE EARTH'S SURFACE

The relief of the continental and oceanic crust is very diverse. But both on land and at the bottom of the Ocean, two main forms stand out: mountains and vast plains. The diversity of relief is explained by the mobility of the earth's crust; the interaction of internal processes of the earth, which create unevenness in the surface of the earth, with external ones, which are aimed at leveling it (weathering, glaciers, wind, flowing waters).

Slide 18

A MOUNTAIN is a convex shape of a surface with a well-defined top, bottom, and slopes. The height of the mountains above the surrounding area is more than 200 meters. More often than not, mountains form MOUNTAIN RANGES

Based on absolute height, they are distinguished: low mountains (up to 1000 m); medium-altitude (from 1000 to 2000 m); high (over 2000 m). The highest mountains on Earth are the Himalayas, and among them is the highest peak - Mount Everest (8848 m).

In mountainous countries, the strongest interaction between internal and external processes occurs. The faster mountains rise, the faster they collapse. Man changes mountains when he extracts minerals, builds roads, and builds tunnels.

Sushi mountains

Slide 19

Most of the land surface is occupied by plains. If a plain has no elevations or depressions, then it is called flat. But hilly plains are more common. Their relief is more diverse: hills, ravines, depressions with lakes, wide river valleys.

Based on absolute height, there are three main types of plains: lowlands (up to 200 m); elevations (from 200 to 500 m); plateaus (more than 500 m). Lowlands and hills are usually covered with thick sedimentary rocks. Plains usually correspond to the most stable parts of the continental crust. Internal processes manifest themselves here in the form of slow vertical oscillations. The diversity or monotony of the relief of the plains is associated with the action of external forces.

Plains are most convenient for human economic activity.

Sushi plains

Slide 20

Mountains and ocean plains

The ocean floor topography includes many volcanoes, both active and extinct, with wave-aligned peaks; individual mountain ranges.

The most important discovery is the mid-ocean ridges in the middle of each ocean - these are swell-like uplifts of the oceanic crust, forming a single chain with a length of more than 70 thousand km. Where the peaks of mid-ocean ridges come to the surface, islands are formed (Iceland).

Most of the ocean floor is occupied by basins, the topography of which is flat. There are areas that are flat and hilly. Volcanic cones rise in some parts of the basins. The bottom of deep-sea plains is covered with sedimentary rocks up to several kilometers thick. One of the types of Ocean plains - continental shallows - are parts of the continent located below the level of the Ocean to a depth of 200 m. Continental shallows are covered mainly with clastic rocks brought by rivers from the land.

The greatest changes in the relief of the oceanic plains are associated with earthquakes, volcanic eruptions, and faults in the earth's crust. The irregularities they create are transformed by external processes. Sedimentary rocks settle to the bottom and level it. In the marginal parts of the oceans, trenches have been discovered; their depth reaches more than 10 km (Mariana Trench - 11022 m).

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Earth's crust- the thin upper shell of the Earth, which has a thickness of 40-50 km on the continents, 5-10 km under the oceans and is only about 1%.

Eight elements - oxygen, silicon, hydrogen, aluminum, iron, magnesium, calcium, sodium - form 99.5% of the earth's crust.

On continents, the crust is three-layered: sedimentary rocks cover granite rocks, and granite rocks overlie basaltic rocks. Under the oceans the crust is of the “oceanic”, two-layer type; sedimentary rocks simply lie on basalts, there is no granite layer. There is also a transitional type of the earth's crust (island-arc zones on the margins of the oceans and some areas on, for example).

The earth's crust has the greatest thickness in mountainous regions (under - over 75 km), average - in areas of platforms (under lowlands - 35-40, within the borders of the Russian platform - 30-35), and the smallest in the central regions of the oceans (5-7 km).

The predominant part of the earth's surface is the plains of continents and the ocean floor. The continents are surrounded by a shelf - a shallow strip with a depth of up to 200 g and an average width of about SO km, which, after a sharp steep bend of the bottom, turns into a continental slope (the slope varies from 15-17 to 20-30° ). The slopes gradually level out and turn into abyssal plains (depths 3.7-6.0 km). The greatest depths (9-11 km) are oceanic, the vast majority of which are located on the northern and western outskirts.

The earth's crust formed gradually: first a basalt layer was formed, then a granite layer; the sedimentary layer continues to form to this day.

Different rocks of the earth's crust, as well as its tectonic structures, are associated with different materials: flammable, metal, construction, and also those that are raw materials for chemical and.

The deep strata of the lithosphere, which are studied by geophysical methods, have a rather complex and still insufficiently studied structure, just like the mantle and core of the Earth. But it is already known that the density of rocks increases with depth, and if on the surface it averages 2.3-2.7 g/cm3, then at a depth of about 400 km it is 3.5 g/cm3, and at a depth of 2900 km ( boundary of the mantle and the outer core) - 5.6 g/cm3. In the center of the core, where the pressure reaches 3.5 thousand t/cm2, it increases to 13-17 g/cm3. The nature of the increase in the Earth's deep temperature has also been established. At a depth of 100 km it is approximately 1300 K, at a depth of approximately 3000 km -4800 K, and in the center of the earth's core - 6900 K.

The predominant part of the Earth's substance is in a solid state, but at the boundary of the earth's crust and the upper mantle (depths of 100-150 km) lies a layer of softened, pasty rocks. This thickness (100-150 km) is called the asthenosphere. Geophysicists believe that other parts of the Earth may also be in a rarefied state (due to decompression, active radio decay of rocks, etc.), in particular, the zone of the outer core. The inner core is in the metallic phase, but today there is no consensus regarding its material composition.

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Presentation on the topic: Earth's crust

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Structure of the Earth Currently, scientists assume that there is a core in the center of the Earth, its radius is about 3500 km. The core is surrounded by a mantle, its thickness is approximately 2900 km. Above the mantle is the earth's crust, its thickness ranges from 5 to 80 km. The earth's crust is the hardest shell. The mantle substance is in a special plastic state; this substance can flow slowly under pressure. The heaviest and densest substances are found in the core; the temperature there is about 3500°.

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Slide description:

What is the lithosphere? The earth's crust consists of three layers: sedimentary, granite, basalt. Each layer of the earth's crust is remarkable in its own way. Sedimentary rocks were formed by the deposition of matter on land or its deposition in an aquatic environment. They lie in layers replacing each other. Behind the sedimentary rocks is a layer of granite. Granite was formed as a result of the eruption and solidification of magma in the earth's crust under conditions of high temperatures and pressure. This is an igneous rock. The next layer of the earth's crust after granite is basalt. Basalt is also of igneous origin. It is heavier than granite and contains more iron, magnesium and calcium. The earth's crust is not the same thickness everywhere. The thickness of the earth's crust is less under the oceans than under the continents. The greatest thickness of the earth's crust is observed under mountain ranges.

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Slide description:

Rocks that make up the earth's crust The earth's crust is composed of a wide variety of minerals and rocks. In these layers you can find deposits of minerals - coal, oil, rock salt. All these minerals are of organic origin. Granite was formed as a result of the eruption and solidification of magma in the earth's crust under conditions of high temperatures and pressure. This is an igneous rock. Basalt is heavier than granite and contains more iron, magnesium and calcium.

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Movements of the earth's crust Scientists believe that the earth's crust is divided by deep faults into blocks or plates of different sizes. These plates move through the liquefied mantle layer relative to each other. There are plates that contain only the crust of the continents (the Eurasian plate). But most plates contain both the crust of the continents and the crust of the ocean floors. In places where plates converge, they collide, one plate moves onto another, and mountain belts, deep-sea trenches, and island arcs are formed. Vivid examples of such formations are the Japanese and Kuril Islands. Scientists associate the movement of plates with the movement of matter in the mantle. What forces move lithospheric plates? These are the internal forces of the Earth, resulting from the decay of radioactive elements that make up the Earth's core.

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The boundaries of lithospheric plates are located both in places of their rupture and in places of collision - these are moving areas of the earth's crust, to which most active volcanoes are confined and where earthquakes are frequent. These areas form the Earth's seismic belts. The Earth's seismic belts include areas of the Pacific coast, the Mediterranean, and the Atlantic coast. The largest seismic belt on Earth is the Pacific Volcanic Belt, or, as it is often called, the Pacific “Ring of Fire.” The more we move away from the boundaries of the moving sections towards the center of the plate, the more stable sections of the earth's crust become. Moscow, for example, is located in the center of the Eurasian plate, and its territory is considered quite seismically stable.

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EARTHQUAKES The displacement of some parts of the earth's crust relative to others in the horizontal and vertical directions at great depths in the lithosphere is called an EARTHQUAKE. The place at depth where a rupture and displacement of rocks is formed is called an EARTHQUAKE FOCUS. The place on the earth's surface located above the source is called the EARTHQUAKE EPICENTER. The most severe destruction occurs at the epicenter, where tremors are directed from bottom to top. Seismological scientists have compiled a scale for measuring the strength of an earthquake in points from 1 to 12. The consequence of earthquakes in the oceans is TSUNAMI.

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Slide description:

VOLCANISM VOLCANO (from Latin “vulcanus” - fire, flame), a geological formation that appears above channels and cracks in the earth’s crust, through which lava, ash, hot gases, water vapor and rock fragments erupt onto the earth’s surface. There are active, dormant and extinct volcanoes, and in shape they are central, erupting from a central channel and fissures, the vents of which look like gaping cracks or a series of small cones. The main parts of a volcano are the magma chamber (in the earth's crust or upper mantle); vent - an outlet channel through which magma rises to the surface; cone - a rise on the surface of the Earth from the products of a volcanic ejection; crater - a depression on the surface of a volcano cone. Modern volcanoes are located along large faults and tectonically mobile areas (mainly on islands and shores of the Pacific and Atlantic Ocean). Active active volcanoes: Klyuchevskaya Sopka and Avachinskaya Sopka (Kamchatka, Russian Federation), Vesuvius (Italy), Izalco (El Salvador), Mauna Loa (Hawaiian Islands), etc.

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HOT SPRINGS AND GEYSERS In areas where there are volcanoes, underground waters have a high temperature and contain various salts and gases in dissolved form, i.e. are mineral. These waters flow to the surface, forming springs, streams, and rivers. Sometimes they burst out like a hot fountain, rising to a height of several tens of meters. Such gushing sources are called GEYSERS. People use hot underground waters to heat rooms and greenhouses (Kamchatka, Iceland). Mineral springs are for medicinal purposes.

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MAIN FORMS OF RELIEF OF THE EARTH'S SURFACE The relief of the continental and oceanic crust is very diverse. But both on land and at the bottom of the Ocean, two main forms stand out: mountains and vast plains. The diversity of relief is explained by the mobility of the earth's crust; the interaction of internal processes of the earth, which create unevenness in the surface of the earth, with external ones, which are aimed at leveling it (weathering, glaciers, wind, flowing waters).

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Slide description:

A MOUNTAIN is a convex shape of a surface with a well-defined top, bottom, and slopes. The height of the mountains above the surrounding area is more than 200 meters. More often, mountains form MOUNTAIN RANGES Based on absolute height, they are distinguished: low mountains (up to 1000 m); medium-altitude (from 1000 to 2000 m); high (over 2000 m). The highest mountains on Earth are the Himalayas, and among them is the highest peak - Mount Everest (8848 m). In mountainous countries, the strongest interaction between internal and external processes occurs. The faster mountains rise, the faster they collapse. Man changes mountains when he extracts minerals, builds roads, and builds tunnels.

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Most of the land surface is occupied by plains. If a plain has no elevations or depressions, then it is called flat. But hilly plains are more common. Their relief is more diverse: hills, ravines, depressions with lakes, wide river valleys. Based on absolute height, there are three main types of plains: lowlands (up to 200 m); elevations (from 200 to 500 m); plateaus (more than 500 m). Lowlands and hills are usually covered with thick sedimentary rocks. Plains usually correspond to the most stable parts of the continental crust. Internal processes manifest themselves here in the form of slow vertical oscillations. The diversity or monotony of the relief of the plains is associated with the action of external forces. Plains are most convenient for human economic activity.

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Slide description:

Ocean Mountains and Plains The ocean floor topography includes many volcanoes, both active and extinct, with wave-aligned peaks; individual mountain ranges. The most important discovery is the mid-ocean ridges in the middle of each ocean - these are swell-like uplifts of the oceanic crust, forming a single chain with a length of more than 70 thousand km. Where the peaks of mid-ocean ridges come to the surface, islands are formed (Iceland). Most of the ocean floor is occupied by basins, the topography of which is flat. There are areas that are flat and hilly. Volcanic cones rise in some parts of the basins. The bottom of deep-sea plains is covered with sedimentary rocks up to several kilometers thick. One of the types of Ocean plains - continental shallows - are parts of the continent located below the level of the Ocean to a depth of 200 m. Continental shallows are covered mainly with clastic rocks brought by rivers from the land. The greatest changes in the relief of the oceanic plains are associated with earthquakes, volcanic eruptions, and faults in the earth's crust. The irregularities they create are transformed by external processes. Sedimentary rocks settle to the bottom and level it. In the marginal parts of the oceans, trenches have been discovered; their depth reaches more than 10 km (Mariana Trench - 11022 m).

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