LITHOSPHERE – INTERIOR OF THE EARTH

The lithosphere is the hard top layer of the Earth or the solid crust. This layer is made up of various minerals and rocks. The lithosphere is covered by a thin layer of soil. The surface of this layer is irregular, consisting of various landforms like plains, valleys, deserts, mountains, and plateaus. The temperature of the lithosphere ranges from a crustal temperature of 0 degrees Celsius to a temperature of the upper mantle of 500 degrees Celsius. The Lithosphere forms the outer layer of the structure of Earth and mainly includes the crust and the uppermost portion of the Earth’s mantle.

Lithosphere: overview

The lithosphere of the Earth constitutes the rigid and hard outer vertical layer of the Earth. This layer is composed of the upper part of the mantle and the crust. It is made up of various minerals and rocks. The lithosphere is covered by a thin soil layer and the cold rock presents 100 km in the upper part of the mantle making the layer very stiff. Lithospheric plates form the upper part of the Earth. These plates move around the Earth’s surface as hard or rigid blocks. 

Lithosphere: definition

The term lithosphere has been derived from the word “sphere” and is combined with the Ancient Greek word “lithos” which means rock. This layer is one of rigid, rocky, and the outermost shell of a terrestrial-type natural satellite or planet. The lithosphere is the underlying cool, the fairly hard upper part of the upper mantle, and the dense layer of the Earth. 

The lithosphere is underlain by the asthenosphere which is the hotter, deeper, and weaker part of the upper mantle. The term asthenosphere which means “a: without; stheno: strength” is the weaker and also the deformed layer of the Earth generally acting as a “lubricant” for the plates of tectonics to slide across the layer. The asthenosphere extends from about 100 km deeper up to nearly 660 km below the surface of the Earth. There is another strongest layer, Mesosphere lying below the asthenosphere. 

Lithosphere Composition 

The lithosphere is composed of both the upper part of the mantle and the crust which behaves like a rigid solid and brittle part. Three main layers of the lithosphere are divided based on their compositions. The crust comprises less than 1% of Earth by mass, which also consists of both continental and oceanic crust. The rock present in the oceanic and continental crust is often felsic in nature. 

Significance of lithosphere 

There is various importance of the Earth’s lithosphere in the lives of living beings. 

• The lithosphere combines with the atmosphere and hydrosphere which provides all living organisms with essential nutrients necessary for their growth. 
• This layer also provides humans with essential materials like iron, silver, calcium, copper, and aluminum, which are used in daily lives. It also provides humans with necessary fuels like gas, coal, and petroleum.
• The lithosphere also consists of water bodies like oceans, lakes, and rivers which are essential for all living organisms to survive on Earth. 

Conclusion

The lithosphere of the Earth is best defined as a crust or a solid shell that protects the earth from outer forces and the harmful rays of the Sun. Below the lithosphere, there is another important layer called the asthenosphere, which is a deep, hot, and weaker layer of the mantle of the Earth. The lithosphere mainly creates a conductive lid right above the upper part of the mantle. This lid helps to reduce the heat transport from the Sun to Earth. This layer is also further classified into two parts such as oceanic and continental lithosphere.