Structure of the Earth

Introduction 

The surface area of the whole earth is very large and broad. The whole internal structure of the earth is subdivided into various layers. Each layer of the earth has different properties and qualities. Each layer of the earth’s structure plays a major role in the whole activities of the earth. All the layers of the earth’s structure are orchestrated like the layers of an onion. The earth’s deepest point consists of the highest temperature; however, as we come upward, the temperature starts decreasing. Then, the uppermost layer is cool. The gravitational pull of the earth influences all these layers. 

Structure of the earth 

Based on composition, the earth’s internal structure is divided into three different layers. These are:

• Core 
• Mantle 
• Crust 

Although, based on the mechanical properties, the earth’s structure is subdivided into two parts. These are: 

• Lithosphere
• Asthenosphere 

Crust 

The crust layer of the earth consists of 1% of the earth’s total mass. This layer is made up of rocks. The internal environment of this layer is very cold, and it is the thinnest layer on the earth. It consists of two more layers. These two layers are:

• Oceanic crust
• Continental crust

Oceanic crust: 

The earth’s oceanic crust is made up of magma. This magma erupted on the seafloor, resulting in basalt lava composition. The basalt lava of the oceanic crust cools and forms an intrusive igneous rock called gabbro. 

Continental crust: 

The continental crust of the earth’s structure is made by the combination of different types of rocks. These are sedimentary rocks and metamorphic rocks. It also consists of granite in large quantities. The continental crust is thicker than the oceanic crust and consists of a low density, due to which it rises higher in the Mantle layer of earth. After sinking into the Mantle, the continental crust forms basins, and when these basins get filled with water, it results in the formation of oceans. 

Mantle 

The Mantle layer is the hottest layer of the structure of the earth. It comprises 68% of the total mass of the earth. It is made up of hard rocks, due to which fundamental constituents of this layer are present in solid form. The seismic waves, meteorites, and heat flow of the whole earth signify that the Mantle layer comprises solid rocks. It continuously releases heat waves, which flow throughout the entire earth. This heat flow is subdivided into two parts. These are:

• Conduction 
• Convection 

Conduction: 

It is defined as the heat flow due to the collisions of atoms present in the earth’s internal structure. The heat is released due to conduct flows from hot areas to the cooler areas. 

Convection:

Convection is the flow of material that results in convection currency in the entire earth. It happens in the same way as the convection in the water pots. 

Core

The core is the ironic layer of the structure of the earth. It covers 31% of the total mass of the earth. It is the centre layer of earth, mainly formed of metallic constituents. The whole Metallic field present on the earth is because of the metals prevented in the earth’s inner core. The core is subdivided into two parts, the outer and inner core. The outer core consists of metal in a liquid state, while the inner core is metal in a solid-state. The magnetic field is formed due to the convection of the current from the inner core to the earth’s outer core. 

Structure of the earth

Let’s understand the structure of the earth.

The uppermost layer of the earth is the crust. Then, the mantle and then the outer core. The inner core is the deepest layer of the earth. Human life lives in the Lithosphere. 

Lithosphere

The Lithosphere combines both the crust and upper Mantle portion of the earth. The upper Mantle in the Lithosphere plays the role of a rigid solid. The Lithosphere is the cool pastry layer of the earth, which is made up of a very rigid solid. 

Asthenosphere

The Asthenosphere is the small part of the molten upper mantle portion of the earth. The upper Mantle plays the role of molten liquid in the Asthenosphere. It is a very weak and malleable portion of the earth’s structure. It is located below the Lithosphere. Although this layer’s upper boundary is defined, the inner layer of the Asthenosphere is not well-defined. 

Conclusion

The internal structure of the earth is divided into various layers. Some layers are present in the molten state, while others are in the solid state. Solid layers are made up of solid metals and rigid rocks, while liquid layers are made of molten metals. The flow of atoms in the molten state of different layers results from the magnetic field on the earth. These layers of the earth’s internal structure result in the formation of oceans, mountains, continents, and islands. These layers are responsible for earthquakes, cyclones and volcanic eruptions. All-natural disasters occur due to the disturbance in layers.