From the mantle, the internal heat of the Earth is transferred to the earth's crust. The upper layer of the earth's crust, to a depth of 20-30 m, is influenced by external temperatures, and below the temperature gradually increases: for every 100 m of depth by +3 C. Deeper, the temperature largely depends on the composition of the rocks.
Exercise: What is the temperature of the rocks in the mine where coal is mined, if its depth is 1000 m, and the temperature of the layer of the earth’s crust, which no longer depends on the season, is +10 C
We decide on actions:
1. How many times will the temperature of rocks increase with depth?
1. By how many degrees does the temperature of the earth’s crust increase in the mine:
3 C 10= 30 C
3. What will be the temperature of the earth's crust in the mine?
10 C+(+30 C)= +40 C
Temperature = +10 C +(1000:100 3 C)=10 C +30 C =40 C
Solve the problem: What is the temperature of the earth’s crust in the mine if its depth is 1600 m, and the temperature of the layer of the earth’s crust, independent of the time of year, is -5 C?
Air temperature =(-5 C)+(1600:100 3 C)=(-5 C)+48 C =+43 C.
Write down the condition of the problem and solve it at home:
What is the temperature of the earth's crust in the mine if its depth is 800 m, and the temperature of the layer of the earth's crust, independent of the time of year, is +8? C?
Solve the problems given in the lesson notes
5. Study of the earth's crust. Working with Fig. 24 p.40, textbook text.
Drilling of the Kola superdeep well began in 1970, its depth is up to 12-15 km. Calculate what part of the earth's radius this is.
R Earth = 6378 km (equatorial)
6356 km (polar) or meridional
530-531 part of the equatorial.
The depth of the deepest mine in the world is 4 times less. Despite numerous studies, we still know very little about the interior of our own planet. In a word, if we turn again to the above comparison, we still cannot “pierce the shell.”
6. Consolidation of new material. Using a multimedia presentation.
Tests and tasks for verification.
1. Determine the shell of the Earth:
1. earth's crust.
2. hydrosphere.
3. atmosphere
4. biosphere.
A. air
B. hard.
G. aquatic.
Verification key:
2. Determine which shell of the Earth we are talking about:
1. Earth's crust
a/ closest to the center of the Earth
b/ thickness from 5 to 70 km
in/ translated from Latin as “blanket”
g/ temperature of the substance +4000 C +5000 C
d/ upper shell of the Earth
e/ thickness about 2900 km
g/ special state of matter: solid and plastic
h/ consists of continental and oceanic parts
and/ the main element of the composition is iron.
Verification key:
The earth according to her internal structure sometimes compared to chicken egg. What do they want to show with this comparison?
Homework: §16, tasks and questions after the paragraph, task in notebook.
Material used by the teacher when explaining a new topic.
Earth's crust.
The Earth's crust on the scale of the entire Earth is a thin film and is insignificant compared to the radius of the Earth. It reaches a maximum thickness of 75 km under the mountain ranges of the Pamirs, Tibet, and the Himalayas. Despite its small thickness, the earth's crust has a complex structure.
Its upper horizons have been studied quite well by drilling wells.
The structure and composition of the earth's crust under the oceans and on the continents is very different. Therefore, it is customary to distinguish two main types of the earth’s crust – oceanic and continental.
The crust of the oceans occupies approximately 56% of the planet's surface, and its main feature is its small thickness - on average about 5-7 km. But even such a thin earth's crust is divided into two layers.
The first layer is sedimentary, represented by clays and calcareous silts. The second layer is composed of basalts - products of volcanic eruptions. The thickness of the basalt layer on the ocean floor does not exceed 2 km.
The continental (mainland) crust occupies an area smaller than the oceanic crust, about 44% of the planet's surface. The continental crust is thicker than the oceanic crust, its average thickness is 35-40 km, and in the mountain region it reaches 70-75 km. It consists of three layers.
The upper layer is composed of various sediments; their thickness in some depressions, for example, in the Caspian lowland, is 20-22 km. Shallow water sediments predominate - limestones, clays, sands, salts and gypsum. The age of the rocks is 1.7 billion years.
The second layer is granite - it is well studied by geologists, because there are outcrops of it to the surface, and attempts were also made to drill through it, although attempts to drill through the entire granite layer were unsuccessful.
The composition of the third layer is not very clear. It is assumed that it should be composed of rocks such as basalts. Its thickness is 20-25 km. The Mohorovicic surface can be traced at the base of the third layer.
Moho surface.
In 1909 on Balkan Peninsula, near Zagreb, a strong earthquake occurred. Croatian geophysicist Andrija Mohorovicic, studying a seismogram recorded at the time of this event, noticed that at a depth of about 30 km the wave speed increases significantly. This observation was confirmed by other seismologists. This means that there is a certain section limiting the earth’s crust from below. To designate it, a special term was introduced - the Mohorovicic surface (or Moho section).
Mantle
Under the crust at depths from 30-50 to 2900 km is the Earth's mantle. What does it consist of? Mainly from rocks rich in magnesium and iron.
The mantle occupies up to 82% of the planet's volume and is divided into upper and lower. The first lies below the Moho surface to a depth of 670 km. A rapid drop in pressure in the upper part of the mantle and high temperature lead to the melting of its substance.
At a depth of 400 km under continents and 10-150 km under oceans, i.e. in the upper mantle, a layer was discovered where seismic waves travel relatively slowly. This layer was called the asthenosphere (from the Greek “asthenes” - weak). Here the proportion of melt is 1-3%, more plastic. Than the rest of the mantle, the asthenosphere serves as a “lubricant” through which rigid lithospheric plates move.
Compared to the rocks that make up the earth's crust, the rocks of the mantle are distinguished by their high density and the speed of propagation of seismic waves in them is noticeably higher.
In the very “basement” of the lower mantle - at a depth of 1000 km and up to the surface of the core - the density gradually increases. What the lower mantle consists of remains a mystery.
Core.
It is assumed that the surface of the core consists of a substance with the properties of a liquid. The core boundary is located at a depth of 2900 km.
But the inner region, starting from a depth of 5100 km, behaves like solid. This is due to very high blood pressure. Even at the upper boundary of the core, the theoretically calculated pressure is about 1.3 million atm. and in the center it reaches 3 million atm. The temperature here can exceed 10,000 C. Each cubic. cm of the substance of the earth's core weighs 12 -14 g.
Apparently, the material in the Earth's outer core is smooth, almost like a cannonball. But it turned out that the differences in the “border” reach 260 km.
Leaf summary of the lesson “Shells of the Earth. Lithosphere. Earth's crust."
Lesson topic. The structure of the Earth and the properties of the earth's crust.
1. Outer shells of the Earth:
Atmosphere - _______________________________________________________________
Hydrosphere -_______________________________________________________________
Lithosphere - ________________________________________________________________
Biosphere - _________________________________________________________________
2. Lithosphere -______________________________________________________________
Compared to the mantle and core, the earth's crust is a very thin, hard and brittle layer. It is composed of a lighter substance, in which about 90 natural chemical elements. These elements are not equally represented in the earth's crust. Seven elements - oxygen, aluminum, iron, calcium, sodium, potassium and magnesium - account for 98% of the mass of the earth's crust (see Fig. 5).
Peculiar combinations of chemical elements form various rocks and minerals. The oldest of them are at least 4.5 billion years old.
Rice. 4. Structure of the earth's crust
Rice. 5. Composition of the earth's crust
Mineral is a relatively homogeneous natural body in its composition and properties, formed both in the depths and on the surface of the lithosphere. Examples of minerals are diamond, quartz, gypsum, talc, etc. (Characteristics physical properties various minerals can be found in Appendix 2.) The composition of the Earth's minerals is shown in Fig. 6.
Rice. 6. General mineral composition of the Earth
Rocks consist of minerals. They can be composed of one or several minerals.
Sedimentary rocks - clay, limestone, chalk, sandstone, etc. - were formed by the precipitation of substances in the aquatic environment and on land. They lie in layers. Geologists call them pages of the history of the Earth, because they can learn about natural conditions that existed on our planet in ancient times.
Among sedimentary rocks, organogenic and inorganogenic (clastic and chemogenic) are distinguished.
Organogenic Rocks are formed as a result of the accumulation of animal and plant remains.
Clastic rocks are formed as a result of weathering, destruction by water, ice or wind of the products of destruction of previously formed rocks (Table 1).
Table 1. Clastic rocks depending on the size of the fragments
Goals and objectives of the lesson:
- introduce students to the main shells of the Earth;
- consider the features of the internal structure of the Earth, the properties of the earth’s crust;
- give an idea of how to study the earth's crust.
Educational and visual complex:
- Globe,
- diagram of the structure of the earth's crust (multimedia presentation),
- textbook for 6th grade “Beginner Course in Geography” Gerasimova T.P., Neklyukova N.P.
Lesson formats:
Acquaintance with the main shells of the Earth, their definition; work with the diagram “Internal structure of the Earth”; work with the table “The Earth’s crust and features of its structure”; a story about ways to study the earth's crust.
Terms and concepts:
- atmosphere,
- hydrosphere,
- lithosphere,
- earth's crust,
- mantle,
- Earth's core,
- continental crust,
- oceanic crust,
- Mohorovicic section,
- ultra-deep wells.
Geographical objects:
Kola Peninsula.
Explanation of new material:
1.Explanatory reading of the textbook, note-taking.
Underline with a pencil and write in your notebook: (using a multimedia presentation).
Outer shells of the earth:
- Air – gaseous shell – atmosphere
- water – water shell – hydrosphere
- rocks that make up the land and ocean floors - earth's crust
- living organisms, together with the environment in which they live, constitute biosphere.
2. The structure of the Earth (consider Fig. 22, p. 39). Use of multimedia presentation. Commented reading, drawing up a sketch in a notebook.
The lithosphere is the solid shell of the Earth, including the earth's crust and top part mantle. The thickness of the lithosphere averages from 70 to 250 km.
Radius of the Earth (equatorial) = 6378 km
3. Properties of the earth's crust. Inclusion in the outline of work with Fig. 23 p.40 (using a multimedia presentation).
The Earth's crust is the hard rocky shell of the Earth, consisting of solid minerals and rocks.
Earth's crust
4. Solving problems to determine the temperature that changes with immersion into the depths of the Earth.
From the mantle, the internal heat of the Earth is transferred to the earth's crust. The upper layer of the earth's crust - to a depth of 20-30 m - is influenced by external temperatures, and below the temperature gradually increases: for every 100 m of depth by + 3C. Deeper, the temperature already largely depends on the composition of the rocks.
Task: What is the temperature of the rocks in the mine where coal is mined, if its depth is 1000 m, and the temperature of the layer of the earth’s crust, which no longer depends on the time of year, is +10C
We decide on actions:
- By how many degrees does the temperature of the earth's crust increase in the mine:
- What will be the temperature of the earth's crust in the mine?
10С+(+30С)= +40С
Temperature = +10C +(1000:100 3C)=10C +30C =40C
Solve the problem: What is the temperature of the earth's crust in a mine if its depth is 1600 m, and the temperature of a layer of the earth's crust that does not depend on the season is -5 C?
Air temperature =(-5C)+(1600:100 3C)=(-5C)+48C =+43C.
Write down the condition of the problem and solve it at home:
What is the temperature of the earth's crust in the mine if its depth is 800 m, and the temperature of the layer of the earth's crust, independent of the time of year, is +8? C?
Solve the problems given in the lesson notes
5. Study of the earth's crust. Working with Fig. 24 p.40, textbook text.
Drilling of the Kola superdeep well began in 1970, its depth is up to 12-15 km. Calculate what part of the earth's radius this is.
R Earth = 6378 km (equatorial)
6356 km (polar) or meridional
530-531 part of the equatorial.
The depth of the deepest mine in the world is 4 times less. Despite numerous studies, we still know very little about the interior of our own planet. In a word, if we turn again to the above comparison, we still cannot “pierce the shell.”
- Consolidation of new material. Using a multimedia presentation .
Tests and tasks for verification.
1. Determine the shell of the Earth: earth's crust.
A. air
B. hard.
G. aquatic.
Verification key:
2. Determine which shell of the Earth we are talking about: Earth's crust
a/ closest to the center of the Earth
b/ thickness from 5 to 70 km
in/ translated from Latin as “blanket”
g/ temperature of the substance +4000 C +5000 C
d/ upper shell of the Earth
e/ thickness about 2900 km
g/ special state of matter: solid and plastic
h/ consists of continental and oceanic parts
and/ the main element of the composition is iron.
Verification key:
3. The earth is sometimes compared to a chicken egg in its internal structure. What do they want to show with this comparison?
Homework: §16, assignments and questions after the paragraph, task in the notebook.
Material used by the teacher when explaining a new topic.
Earth's crust.
The Earth's crust on the scale of the entire Earth is a thin film and is insignificant compared to the radius of the Earth. It reaches a maximum thickness of 75 km under the mountain ranges of the Pamirs, Tibet, and the Himalayas. Despite its small thickness, the earth's crust has a complex structure.
Its upper horizons have been studied quite well by drilling wells.
The structure and composition of the earth's crust under the oceans and on the continents is very different. Therefore, it is customary to distinguish two main types of the earth’s crust – oceanic and continental.
The crust of the oceans occupies approximately 56% of the planet's surface, and its main feature is its small thickness - on average about 5-7 km. But even such a thin earth's crust is divided into two layers.
The first layer is sedimentary, represented by clays and calcareous silts. The second layer is composed of basalts - products of volcanic eruptions. The thickness of the basalt layer on the ocean floor does not exceed 2 km.
The continental (mainland) crust occupies an area smaller than the oceanic crust, about 44% of the planet's surface. The continental crust is thicker than the oceanic crust, its average thickness is 35-40 km, and in the mountain region it reaches 70-75 km. It consists of three layers.
The upper layer is composed of various sediments; their thickness in some depressions, for example, in the Caspian lowland, is 20-22 km. Shallow water sediments predominate - limestones, clays, sands, salts and gypsum. The age of the rocks is 1.7 billion years.
The second layer is granite - it is well studied by geologists, because there are outcrops of it to the surface, and attempts were also made to drill through it, although attempts to drill through the entire granite layer were unsuccessful.
The composition of the third layer is not very clear. It is assumed that it should be composed of rocks such as basalts. Its thickness is 20-25 km. The Mohorovicic surface can be traced at the base of the third layer.
Moho surface.
In 1909 On the Balkan Peninsula, near the city of Zagreb, a strong earthquake occurred. Croatian geophysicist Andrija Mohorovicic, studying a seismogram recorded at the time of this event, noticed that at a depth of about 30 km the wave speed increases significantly. This observation was confirmed by other seismologists. This means that there is a certain section limiting the earth’s crust from below. To designate it, a special term was introduced - the Mohorovicic surface (or Moho section).
Under the crust at depths from 30-50 to 2900 km is the Earth's mantle. What does it consist of? Mainly from rocks rich in magnesium and iron.
The mantle occupies up to 82% of the planet's volume and is divided into upper and lower. The first lies below the Moho surface to a depth of 670 km. A rapid drop in pressure in the upper part of the mantle and high temperature lead to the melting of its substance.
At a depth of 400 km under continents and 10-150 km under oceans, i.e. in the upper mantle, a layer was discovered where seismic waves travel relatively slowly. This layer was called the asthenosphere (from the Greek “asthenes” - weak). Here the proportion of melt is 1-3%, more plastic. Than the rest of the mantle, the asthenosphere serves as a “lubricant” through which rigid lithospheric plates move.
Compared to the rocks that make up the earth's crust, the rocks of the mantle are distinguished by their high density and the speed of propagation of seismic waves in them is noticeably higher.
In the very “basement” of the lower mantle - at a depth of 1000 km and up to the surface of the core - the density gradually increases. What the lower mantle consists of remains a mystery.
It is assumed that the surface of the core consists of a substance with the properties of a liquid. The core boundary is located at a depth of 2900 km.
But the inner region, starting from a depth of 5100 km, behaves like a solid body. This is due to very high blood pressure. Even at the upper boundary of the core, the theoretically calculated pressure is about 1.3 million atm. and in the center it reaches 3 million atm. Temperatures here can exceed 10,000C. Every cube. cm of the substance of the earth's core weighs 12 -14 g.
Apparently, the material in the Earth's outer core is smooth, almost like a cannonball. But it turned out that the differences in the “border” reach 260 km.
- oceanic crust.
- continental crust
- mantle
- core
A. consists of granite, basalt and sedimentary rocks.
b. temperature +2000, viscous state, closer to solid.
V. layer thickness is 3-7 km.
g. temperature from 2000 to 5000C, solid, consists of two layers.
_______________________________________________________________________________
- Solve problems:
________________________________________________________________________________
The Earth is located close enough to the Sun that the energy received is enough to maintain heat and the existence of liquid water. Mainly due to this, our planet is suitable for life.
As we remember from geography lessons, the Earth consists of different layers. The further to the center of the planet, the more tense the situation becomes. Luckily for us, the crust, the topmost geological layer, has relatively stable and comfortable temperatures. However, its meanings can vary greatly depending on place and time.
Johan Swanepoel | shutterstock.com
Structure of the Earth
Like other terrestrial planets, our planet is composed of silicate rocks and metals that differentiate between a solid metallic core, a molten outer core, a silicate mantle, and a crust. The inner core has an approximate radius of 1220 km, and the outer core is about 3400 km.
Then comes the mantle and the earth's crust. The thickness of the mantle is 2890 km. This is the thickest layer of the Earth. It consists of silicate rocks rich in iron and magnesium. High temperatures inside the mantle make the solid silicate material quite plastic.
The upper layer of the mantle is divided into lithosphere and asthenosphere. The first consists of the crust and the cold, rigid upper part of the mantle, while the asthenosphere has some plasticity, which makes the lithosphere covering it unstable and mobile.
Earth's crust
The crust is the outer shell of the Earth and makes up only 1% of its total mass. The thickness of the bark varies depending on the location. On continents it can reach 30 km, and under the oceans it is only 5 km.
The shell consists of many igneous, metamorphic and sedimentary rocks and is represented by a system of tectonic plates. These plates float above the Earth's mantle, and presumably convection in the mantle causes them to be in constant motion.
Sometimes tectonic plates collide, move apart, or slide against each other. All three types of tectonic activity underlie the formation of the earth's crust and lead to periodic renewal of its surface over millions of years.
Temperature range
On the outer layer of the crust, where it comes into contact with the atmosphere, its temperature coincides with the air temperature. Thus, it can reach temperatures up to 35°C in the desert and below zero in Antarctica. On average, the surface temperature of the bark is about 14 °C.
As you can see, the range of values is quite wide. But it is worth considering the fact that most of the earth's crust lies under the oceans. Away from the sun, where it meets water, the temperature can be only 0...+3 °C.
If you start digging a hole in the continental crust, the temperature will increase noticeably. For example, at the bottom of the world's deepest mine, Tau-Tona (3.9 km) in South Africa it reaches 55 °C. The miners who work there all day cannot do without air conditioning.
Thus, average surface temperatures can vary from sweltering heat to bitterly cold depending on location (on land or under water), seasons, and time of day.
And yet the earth's crust remains the only place in solar system, where the temperature is stable enough for life to continue to thrive. Add to this our viable atmosphere and protective magnetosphere, and we are truly lucky!
The Earth is located close enough to the Sun that the energy received is enough to maintain heat and the existence of liquid water. Mainly due to this, our planet is suitable for life.
As we remember from geography lessons, the Earth consists of different layers. The further to the center of the planet, the more tense the situation becomes. Luckily for us, the crust, the topmost geological layer, has relatively stable and comfortable temperatures. However, its meanings can vary greatly depending on place and time.
Structure of the Earth
Like other terrestrial planets, our planet is composed of silicate rocks and metals that differentiate between a solid metallic core, a molten outer core, a silicate mantle, and a crust. The inner core has an approximate radius of 1220 km, and the outer core is about 3400 km.
Then comes the mantle and the earth's crust. The thickness of the mantle is 2890 km. This is the thickest layer of the Earth. It consists of silicate rocks rich in iron and magnesium. High temperatures inside the mantle make the solid silicate material quite plastic.
The upper layer of the mantle is divided into lithosphere and asthenosphere. The first consists of the crust and the cold, rigid upper part of the mantle, while the asthenosphere has some plasticity, which makes the lithosphere covering it unstable and mobile.
Earth's crust
The crust is the outer shell of the Earth and makes up only 1% of its total mass. The thickness of the bark varies depending on the location. On continents it can reach 30 km, but under the oceans it can be only 5 km.
The shell consists of many igneous, metamorphic and sedimentary rocks and is represented by a system of tectonic plates. These plates float above the Earth's mantle, and presumably convection in the mantle causes them to be in constant motion.
Sometimes tectonic plates collide, move apart, or slide against each other. All three types of tectonic activity underlie the formation of the earth's crust and lead to periodic renewal of its surface over millions of years.
Temperature range
On the outer layer of the crust, where it comes into contact with the atmosphere, its temperature coincides with the air temperature. Thus, it can reach temperatures up to 35°C in the desert and below zero in Antarctica. On average, the surface temperature of the bark is about 14 °C.
As you can see, the range of values is quite wide. But it is worth considering the fact that most of the earth's crust lies under the oceans. Away from the sun, where it meets water, the temperature can be only 0...+3 °C.
If you start digging a hole in the continental crust, the temperature will increase noticeably. For example, at the bottom of the world's deepest mine, Tau Tona (3.9 km) in South Africa, it reaches 55 °C. The miners who work there all day cannot do without air conditioning.
Thus, average surface temperatures can vary from sweltering heat to bitterly cold depending on location (on land or under water), seasons, and time of day.
Yet the Earth's crust remains the only place in the solar system where the temperature is stable enough for life to continue to thrive. Add to this our viable atmosphere and protective magnetosphere, and we are truly lucky!