It is difficult to directly estimate the internal structure of the Earth। Because we have been able to study to a depth of a few kilometers from Bhuparpati on Earth। The gold mines of South Africa are 3 to 4 kilometers deep। Amplification to a depth of 12 km has been carried out ( Drill) in the cola region ( Kola) in the Arctic Ocean। It is impossible to get deeper than this, because the temperature is very high at such a depth। Therefore, it is not possible that someone can reach the center of the earth and inspect it and get a sample of the substances there। Yet it is nothing short of a surprise that even under such circumstances our scientists, Have been able to tell us how the structure of the geology is and how deep the substances are found।

In such a situation, geologists have come to know about the internal structure of the Earth with some indirect evidence। These are indirect evidence - density, pressure, temperature, meteorology and seismology। Scholars have given different types of views about the internal structure of the Earth based on these evidences।

Sources or evidence knowing the internal structure of the Earth

1.Density:-

The average density of the entire Earth is 5.5। The density of rocks found on the ground page (Crust) is less than 3। While the density of the rocks of the geology is much higher than 3। This implies that the geo page is composed of light rocks, while the structure of the geology is made up of heavier rocks or matter than the rocks of the geo page।

2.Pressure:-

The upper rocks on the earth exert pressure on the rocks below which increases its density। It is therefore possible that the rocks of the geology will have the highest pressure and due to this, rocks of greater density are found in the geology। It has been attested by modern experiments that every rock has a boundary beyond which its density cannot be increased, No matter how much pressure is increased on him। It therefore concludes that if the greater density of the inner part of the Earth is not due to the greater pressure, it is itself made up of heavier and higher density materials। Such as from heavy materials or metals such as iron and nickel। The Earth's magnetic state is also attested due to this fact।

3. Temperature:-

normally the temperature increases at a rate of 1° C ( 1 ° C ) at a depth of 32 km due to the dissolution of radioactive materials when moving from the ground to the geology is। Thus 3°C at a depth of 100 m, a km. At about 30°C, 10 km. At 300°C, 100 km. At 3000°C, 1000 km. At 30,000°C and central part 6378 km. Must have temperatures greater than 1,90,000 °C at a depth of। The central part must be in a completely molten state due to high temperature। but it's not like that। Studies of seismic waves have proved that the underside of the Earth's land page (Crust) is definitely in the liquid state, The inner central part, known as the crop (Core), is solid despite the thermal state of the Earth। Because there is pressure all around on it।

4. Meteorites:-

Meteorites also come under the solar family in addition to Earth etc. planets। It is believed that these meteorites separated and spread to the solar system at the time of planetary origin । We also see these meteor bodies falling from the sky to the earth at night। The internal structure of the Earth has been estimated based on these meteor bodies। Because meteorites are composed of heavy elements such as nickel and iron। Therefore, it can be concluded that these elements will definitely be in the inner structure of the Earth।

5.Seismology:-

Earth's most important source of internal structure has been considered seismology। Under this, seismic waves are measured by seismograph ( earthquake-earthquake instrument )। The place inside the Earth where the earthquake originates is called the Earthquake Center ( Focus)। And just above the ground page where seismic waves are first experienced। It is called earthquake overeat ( Epicenter)। During the earthquake, three types of tiranges are produced in the earth।

1. The primary bottomless longitudinal trange that is prevalent as the P wave। P waves have the highest transmission velocity। It starts from the earthquake center within the Earth and solids of the Earth, The ground crossing all types of liquid and gaseous fields reaches the top of the page before any other wave।

2. Secondary bottomless transverse trunks that are prevalent as S waves। The transmission velocity of S waves is relatively low compared to P waves। S trange can only pass through solid medium। These tiranges become extinct in the liquid part। And P waves arrive a little late।

3. Tertiary means the plane of the plane which is prevalent as L wave। The transmission velocity of L waves is much lower than that of P and S waves। These earthquakes originate from the overestra and move slowly, and remain confined on the ground।

Information on the internal structure of the Earth from seismic waves

The above seismic waves study makes it known that if the Earth's structure was from rocks of equal density, the transmission velocity and path of seismic waves would be the same at all locations And the straightforward inspection of these seismic waves makes it known that the actual situation is something else।

•  Waves passing through greater depths take relatively short periods of time despite long distances to reach the zenithra। It is clear from this that the transmission velocity of waves increases with depth। Seismic waves theorize that the speed of waves is reduced in low density rocks and higher density rocks। It can therefore be concluded that there is a variation in the elements of the inner parts from the upper parts of the earth and the structure of the inner parts is made of non-heavy density materials।

• When passing in greater depths, waves have to adopt the Waqrakar path। This makes it known that the chemical composition of the inner layers of the Earth is not uniform

•  Some seismic waves return to the ground after going deep। And again the plane is partially converted towards the depth।

• The s sway disappears at a distance of 120° from the overestra। This meant that the S trange is absent in the central part of the Earth। While the P tricolor falls very dim। Why does this happen? The principle of waves is that “ they cannot pass into the liquid part! ” Therefore, it can be concluded that the central part of the Earth will be in the liquid state। Olham stated on the same basis that after a depth of 2900 kilometers the central part of the Earth is liquid। The dim reading of P waves also proves to be the liquid state of the rocks।

• P trange is converted (Refracted) when entering and exiting the central part of the Earth। That is, it turns। And comes to the ground in the opposite direction of the overestra। This leaves a part on the ground where no seismic wave reaches the zenithra। This part is called “ Earthquake Shadowfield ” ( Shadow zone)।

Earth's internal structure based on seismic waves

Finally, the internal structure of the Earth is divided into three layers as the following, assuming the base of the seismic waves।

1.Crust

2.Mantle

3.Core

1.Crust: - 

Depth 33 km, density 2.7 to 2.9

Geo Page Athwa Bhuparpati Athwa Crust (Crust) is the subset of the Earth। Its extension is about 33 kilometers from the ground floor। This part is very brittle and has the ability to break quickly। The thickness of the hermaphroditism varies under continents and the ocean। Average thickness of heronity below continents where up to 30 kilometers। At the same time, the average thickness of the crust under the oceans is only about 5 kilometers। The thickness of the Bhuparpati under the Himalayan mountain garland is about 70 kilometers। The hermaphroditism is mainly formed from minerals such as felfpar and elements such as oxygen, silica, almunium and iron।

The Bhuparpati is again divided into two parts based on the difference in seismic waves। Upper Bhuparpati and Lower Bhuparpati। In the upper Bhuparpati where the speed of P waves is 6.1 kilometers per second। At the same time it increases to 6.9 km per second in the lower Bhuparatti। The density variation between upper and lower hermitage is known as “ Konrad affiliation ”। The lower layer of the heron is made up of ultra-alkaline rocks। The upper layer of the hermaphroditic and upper mantle is included under ‘ the terrestrial ’ ( Lithosphere)। Its thickness varies across continents and oceans। Earthquakes usually also fall in this circle।

2.Mantle: -

 Depth 33 – 2900 km, density 3.0 to 5.0

The layer found just below the Bhuparpatty is known as Pravar Athwa Mantal ( Mantle)। Its extension ranges from 33 kilometers to a depth of 2900 kilometers। The simultaneous increase in the speed of seismic waves below the lower ground page indicates the presence of the upper mantle layer। Because where the speed of P waves in the lower Bhuparati is 6.9 kilometers per second। At the same time, it increases from 7.9 km to 8.1 km per second in Mantle। This sudden increase in seismic waves is known as “ Moh disambiguation ”।

The highest 83% of the entire Earth's volume and about 60% of the mass exist as mantle। The average density of mantal ranges from 3.5 to 5.5। Mantle is also divided into two parts based on the variation in seismic waves। As upper mantal and lower mantal। The upper mantal layer extends from 33 kilometers to 700 kilometers and the lowly mantal 700 kilometers to 2900 kilometers।

The upper mantle layer is made of strong rocks with high density and has a predominance of heavy minerals such as magnesium and iron। The average density of overhead mantle is 4.5। The temperature here is found to be around 1900° C ( Celsius )। The upper part of the upper canal is called ‘ debilitator ’ ( Asthenosphere)। Lava, ash, gas originate mainly from this part during volcanic action। The disambiguation separating the upper mantle layer from the lower mantle layer is known as “ Rapti disambiguation ”।

The lower mandal layer is known as ‘ mediumland ’ ( Mesosphere)। The lower mantle is mainly made up of oligine rocks। Its depth ranges from 700 kilometers to 2900 kilometers। Its average density is 5.5। While the temperature is found to be around 3300 °C। Disambiguation is found based on the speed of seismic waves in the lower mantle and upper crust। Which is known as “ Gutenberg disambiguation ”। It separates the lower mantle and overhead crusts।

3. Core: - 

Depth 2900 – 6378 km, density 5.0 to 14.0

Geopot (Core) Athwa Antram is the most internal part of the Earth found below the mantle to the center of the Earth। This layer is also called berisphere ( Beryshphere)। Its depth ranges from 2900 kilometers to 6378 kilometers। The density of this layer is twice that of Mantle। At the same time, only 16% of the volume of the Earth and mass is 32। The average temperature of the crutches is 5500 ° C and density 13 as estimated। It is mainly made of heavy elements such as nickel and iron। Hence it is also known as Nife ( NiFe)। It is the productive part of the Earth's magnetic field।

The crutches are divided into two sub-parts depending on the speed of the waves - the external crutches and the internal crutches। The external cradle shows the density variation between internal crutches known as “ Lehman disambiguation ”। The outer cradle extends from 2900 kilometers to 5100 kilometers। S trange does not enter this part becomes extinct। This leads to the conclusion that the ‘ external cradle ’ part is in the liquid state।

Internal crunch 5100 km. From the center of the earth 6378 km. Extends to। The density of this inner core is 13.6। This part exists in solid bottomless plastic form। The speed of P waves in the inner crumbling part increased to about 11.23 km. It becomes per second।

Discontinuity

An infection zone found between layers of the Earth where the characteristics of two layers are present simultaneously is called disambiguation (Discontinuity)। There are mainly two types of disambiguation ( Discontinuity) found on Earth - Moho and Gutenberg disambiguation। Additionally some more disambiguation is found, details of which you can see further।

● Discontinuity: - 5 to 10 km in the middle of the upper heron and lower heron. The transition zone located at the depth of is called conard Discontinuity।

● Moho Discontinuity: - about 30 km between lower heron and upper mantal.The transition zone located at the depth of is known as Moho Discontinuity।

● Rapti Discontinuity: - The transition zone located in the middle of the upper and lower mantle at a depth of about 700 kilometers is known as Rapti Discontinuity।

● Gutenberg Discontinuity: - The transition zone located between the lower mantle and the overhead crop at a depth of about 2900 kilometers is known as the Gutenberg Discontinuity।

● Lehman Discontinuity: - The transition zone located at a depth of about 5100 kilometers in the middle of the outer and inner crood is known as Lehman Discontinuity।

It is difficult to directly estimate the internal structure of the Earth। Because we have been able to study to a depth of a few kilometers from Bhuparpati on Earth। The gold mines of South Africa are 3 to 4 kilometers deep। Amplification to a depth of 12 km has been carried out ( Drill) in the cola region ( Kola) in the Arctic Ocean। It is impossible to get deeper than this, because the temperature is very high at such a depth। Therefore, it is not possible that someone can reach the center of the earth and inspect it and get a sample of the substances there। Yet it is nothing short of a surprise that even under such circumstances our scientists, Have been able to tell us how the structure of the geology is and how deep the substances are found।

In such a situation, geologists have come to know about the internal structure of the Earth with some indirect evidence। These are indirect evidence - density, pressure, temperature, meteorology and seismology। Scholars have given different types of views about the internal structure of the Earth based on these evidences।

Sources or evidence knowing the internal structure of the Earth

1.Density:-

The average density of the entire Earth is 5.5। The density of rocks found on the ground page (Crust) is less than 3। While the density of the rocks of the geology is much higher than 3। This implies that the geo page is composed of light rocks, while the structure of the geology is made up of heavier rocks or matter than the rocks of the geo page।

2.Pressure:-

The upper rocks on the earth exert pressure on the rocks below which increases its density। It is therefore possible that the rocks of the geology will have the highest pressure and due to this, rocks of greater density are found in the geology। It has been attested by modern experiments that every rock has a boundary beyond which its density cannot be increased, No matter how much pressure is increased on him। It therefore concludes that if the greater density of the inner part of the Earth is not due to the greater pressure, it is itself made up of heavier and higher density materials। Such as from heavy materials or metals such as iron and nickel। The Earth's magnetic state is also attested due to this fact।

3. Temperature:-

normally the temperature increases at a rate of 1° C ( 1 ° C ) at a depth of 32 km due to the dissolution of radioactive materials when moving from the ground to the geology is। Thus 3°C at a depth of 100 m, a km. At about 30°C, 10 km. At 300°C, 100 km. At 3000°C, 1000 km. At 30,000°C and central part 6378 km. Must have temperatures greater than 1,90,000 °C at a depth of। The central part must be in a completely molten state due to high temperature। but it's not like that। Studies of seismic waves have proved that the underside of the Earth's land page (Crust) is definitely in the liquid state, The inner central part, known as the crop (Core), is solid despite the thermal state of the Earth। Because there is pressure all around on it।

4. Meteorites:-

Meteorites also come under the solar family in addition to Earth etc. planets। It is believed that these meteorites separated and spread to the solar system at the time of planetary origin । We also see these meteor bodies falling from the sky to the earth at night। The internal structure of the Earth has been estimated based on these meteor bodies। Because meteorites are composed of heavy elements such as nickel and iron। Therefore, it can be concluded that these elements will definitely be in the inner structure of the Earth।

5.Seismology:-

Earth's most important source of internal structure has been considered seismology। Under this, seismic waves are measured by seismograph ( earthquake-earthquake instrument )। The place inside the Earth where the earthquake originates is called the Earthquake Center ( Focus)। And just above the ground page where seismic waves are first experienced। It is called earthquake overeat ( Epicenter)। During the earthquake, three types of tiranges are produced in the earth।

1. The primary bottomless longitudinal trange that is prevalent as the P wave। P waves have the highest transmission velocity। It starts from the earthquake center within the Earth and solids of the Earth, The ground crossing all types of liquid and gaseous fields reaches the top of the page before any other wave।

2. Secondary bottomless transverse trunks that are prevalent as S waves। The transmission velocity of S waves is relatively low compared to P waves। S trange can only pass through solid medium। These tiranges become extinct in the liquid part। And P waves arrive a little late।

3. Tertiary means the plane of the plane which is prevalent as L wave। The transmission velocity of L waves is much lower than that of P and S waves। These earthquakes originate from the overestra and move slowly, and remain confined on the ground।

Information on the internal structure of the Earth from seismic waves

The above seismic waves study makes it known that if the Earth's structure was from rocks of equal density, the transmission velocity and path of seismic waves would be the same at all locations And the straightforward inspection of these seismic waves makes it known that the actual situation is something else।

•  Waves passing through greater depths take relatively short periods of time despite long distances to reach the zenithra। It is clear from this that the transmission velocity of waves increases with depth। Seismic waves theorize that the speed of waves is reduced in low density rocks and higher density rocks। It can therefore be concluded that there is a variation in the elements of the inner parts from the upper parts of the earth and the structure of the inner parts is made of non-heavy density materials।

• When passing in greater depths, waves have to adopt the Waqrakar path। This makes it known that the chemical composition of the inner layers of the Earth is not uniform

•  Some seismic waves return to the ground after going deep। And again the plane is partially converted towards the depth।

• The s sway disappears at a distance of 120° from the overestra। This meant that the S trange is absent in the central part of the Earth। While the P tricolor falls very dim। Why does this happen? The principle of waves is that “ they cannot pass into the liquid part! ” Therefore, it can be concluded that the central part of the Earth will be in the liquid state। Olham stated on the same basis that after a depth of 2900 kilometers the central part of the Earth is liquid। The dim reading of P waves also proves to be the liquid state of the rocks।

• P trange is converted (Refracted) when entering and exiting the central part of the Earth। That is, it turns। And comes to the ground in the opposite direction of the overestra। This leaves a part on the ground where no seismic wave reaches the zenithra। This part is called “ Earthquake Shadowfield ” ( Shadow zone)।

Earth's internal structure based on seismic waves

Finally, the internal structure of the Earth is divided into three layers as the following, assuming the base of the seismic waves।

1.Crust

2.Mantle

3.Core

1.Crust: - 

Depth 33 km, density 2.7 to 2.9

Geo Page Athwa Bhuparpati Athwa Crust (Crust) is the subset of the Earth। Its extension is about 33 kilometers from the ground floor। This part is very brittle and has the ability to break quickly। The thickness of the hermaphroditism varies under continents and the ocean। Average thickness of heronity below continents where up to 30 kilometers। At the same time, the average thickness of the crust under the oceans is only about 5 kilometers। The thickness of the Bhuparpati under the Himalayan mountain garland is about 70 kilometers। The hermaphroditism is mainly formed from minerals such as felfpar and elements such as oxygen, silica, almunium and iron।

The Bhuparpati is again divided into two parts based on the difference in seismic waves। Upper Bhuparpati and Lower Bhuparpati। In the upper Bhuparpati where the speed of P waves is 6.1 kilometers per second। At the same time it increases to 6.9 km per second in the lower Bhuparatti। The density variation between upper and lower hermitage is known as “ Konrad affiliation ”। The lower layer of the heron is made up of ultra-alkaline rocks। The upper layer of the hermaphroditic and upper mantle is included under ‘ the terrestrial ’ ( Lithosphere)। Its thickness varies across continents and oceans। Earthquakes usually also fall in this circle।

2.Mantle: -

 Depth 33 – 2900 km, density 3.0 to 5.0

The layer found just below the Bhuparpatty is known as Pravar Athwa Mantal ( Mantle)। Its extension ranges from 33 kilometers to a depth of 2900 kilometers। The simultaneous increase in the speed of seismic waves below the lower ground page indicates the presence of the upper mantle layer। Because where the speed of P waves in the lower Bhuparati is 6.9 kilometers per second। At the same time, it increases from 7.9 km to 8.1 km per second in Mantle। This sudden increase in seismic waves is known as “ Moh disambiguation ”।

The highest 83% of the entire Earth's volume and about 60% of the mass exist as mantle। The average density of mantal ranges from 3.5 to 5.5। Mantle is also divided into two parts based on the variation in seismic waves। As upper mantal and lower mantal। The upper mantal layer extends from 33 kilometers to 700 kilometers and the lowly mantal 700 kilometers to 2900 kilometers।

The upper mantle layer is made of strong rocks with high density and has a predominance of heavy minerals such as magnesium and iron। The average density of overhead mantle is 4.5। The temperature here is found to be around 1900° C ( Celsius )। The upper part of the upper canal is called ‘ debilitator ’ ( Asthenosphere)। Lava, ash, gas originate mainly from this part during volcanic action। The disambiguation separating the upper mantle layer from the lower mantle layer is known as “ Rapti disambiguation ”।

The lower mandal layer is known as ‘ mediumland ’ ( Mesosphere)। The lower mantle is mainly made up of oligine rocks। Its depth ranges from 700 kilometers to 2900 kilometers। Its average density is 5.5। While the temperature is found to be around 3300 °C। Disambiguation is found based on the speed of seismic waves in the lower mantle and upper crust। Which is known as “ Gutenberg disambiguation ”। It separates the lower mantle and overhead crusts।

3. Core: - 

Depth 2900 – 6378 km, density 5.0 to 14.0

Geopot (Core) Athwa Antram is the most internal part of the Earth found below the mantle to the center of the Earth। This layer is also called berisphere ( Beryshphere)। Its depth ranges from 2900 kilometers to 6378 kilometers। The density of this layer is twice that of Mantle। At the same time, only 16% of the volume of the Earth and mass is 32। The average temperature of the crutches is 5500 ° C and density 13 as estimated। It is mainly made of heavy elements such as nickel and iron। Hence it is also known as Nife ( NiFe)। It is the productive part of the Earth's magnetic field।

The crutches are divided into two sub-parts depending on the speed of the waves - the external crutches and the internal crutches। The external cradle shows the density variation between internal crutches known as “ Lehman disambiguation ”। The outer cradle extends from 2900 kilometers to 5100 kilometers। S trange does not enter this part becomes extinct। This leads to the conclusion that the ‘ external cradle ’ part is in the liquid state।

Internal crunch 5100 km. From the center of the earth 6378 km. Extends to। The density of this inner core is 13.6। This part exists in solid bottomless plastic form। The speed of P waves in the inner crumbling part increased to about 11.23 km. It becomes per second।

Discontinuity

An infection zone found between layers of the Earth where the characteristics of two layers are present simultaneously is called disambiguation (Discontinuity)। There are mainly two types of disambiguation ( Discontinuity) found on Earth - Moho and Gutenberg disambiguation। Additionally some more disambiguation is found, details of which you can see further।

● Discontinuity: - 5 to 10 km in the middle of the upper heron and lower heron. The transition zone located at the depth of is called conard Discontinuity।

● Moho Discontinuity: - about 30 km between lower heron and upper mantal.The transition zone located at the depth of is known as Moho Discontinuity।

● Rapti Discontinuity: - The transition zone located in the middle of the upper and lower mantle at a depth of about 700 kilometers is known as Rapti Discontinuity।

● Gutenberg Discontinuity: - The transition zone located between the lower mantle and the overhead crop at a depth of about 2900 kilometers is known as the Gutenberg Discontinuity।

● Lehman Discontinuity: - The transition zone located at a depth of about 5100 kilometers in the middle of the outer and inner crood is known as Lehman Discontinuity।