Layers of the Earth

Different technological advances have allowed us to learn a lot about the Earth and the layers that compose it. Each layer has its own properties , composition and characteristics that affect many of the key processes on our planet. They are, in order from the outside to the inside: the crust , the mantle , the outer core , and the inner core . The layers of the Earth will provide the geologists and geophysicistsa series of clues about how the Earth formed, the layers that make up other planetary bodies, the source of Earth’s resources, and much more. Modern advancements have allowed scientists to study what lies beneath our feet in more detail than ever before, and yet there are still significant gaps in our understanding.

What are the layers of the earth?

They are the four different layers that are forming the earth which can be internal and external layers , and those that have unique and different characteristics depending on the place where they are located.

  • Types
  • What are the layers of the Earth
  • features
  • Composition of the Earth’s layers
  • Features


Earth can be divided in one of two ways: mechanically or chemically . Mechanically, or geologically , that is, the study of liquid states can be divided into lithosphere , asthenosphere , mesospheric mantle, outer core and inner core. But chemically , which is the more popular of the two, it can be divided into the crust , the mantle (which can be subdivided into the upper and lower mantle) and the core , which can also be subdivided into the outer core, and central core. .

The inner core is solid, the outer core is liquid, and the mantle is solid / plastic. This is due to the relative melting points of the different layers and the increase in temperature and pressure as depth increases . On the surface, nickel-iron alloys and silicates are cool enough to be solid. In the upper mantle, the silicates are generally solid, but there are localized regions of melt that lead to limited viscosity.

What are the layers of the Earth

The layers of the earth are as follows:

The crust

This layer is the outer , the most of the planet cold and hard on Earth that has a depth of about 5-70 km. It forms 1% of the total volume of the Earth, although it constitutes the entire surface, this means the continents and the bottom of the ocean . The oceanic crust is made up of dense material like igneous rocks and the less dense continental crust is made up of sodium potassium aluminum silicate rocks , like granite.

The highest section of the mantle together with the crust form the lithosphere, it is fragile and can be broken very easily.

The mantle

The upper mantle represents about 84% of the volume of the Earth, it is predominantly solid , but it behaves like a very viscous fluid . The upper mantle and crust make up the lithosphere , which is relatively rigid on top but becomes noticeably more plastic below.

The movement in the mantle or convection is expressed at the surface through the movements of the tectonic plates . This process is responsible for continental drift , earthquakes , the formation of mountain ranges and other geological processes.

It is between 660 and 2,891 km deep . Temperatures in this region of the planet can reach over 4,000 ° C at the core boundary, far exceeding the melting points of mantle rocks. However, due to the enormous pressure exerted on the mantle, the viscosity and melting are very limited compared to the upper mantle. Very little is known about the lower mantle, other than that it appears to be seismically homogeneous.

The nucleus

The outer core is liquid and has a thickness of 2,300 km extending in a radius of 3,400 km. The outer core is believed to be 80% iron , along with nickel and other lighter elements.

The temperature of the outer core varies from 4,030 ° C in the outer regions to 5,730 ° C in the part closest to the inner core. Because of its high temperature, the outer core is in a fluid state of low viscosity which undergoes convection turbulent and rotates faster than the rest of the planet.

The inner core is composed primarily of iron and nickel and has a radius of 1,220 km. The density in the core varies between 12,600 and 13,000 kg / m3, suggesting that there must also be a large number of heavy elements there, such as gold, platinum, palladium, silver, and tungsten. The inner core temperature is estimated to be about 5,400 ° C.


The main characteristics of the layers of the earth are the following:

  • The crust is divided into plates and has two important types of crust, the terrestrial and the continental .
  • The mantle is the largest layer that the planet has and is divided into upper and lower mantles .
  • The core is made of very dense materials and its temperatures are extremely high.

Composition of the Earth’s layers

The crust of the earth is composed of mafic rocks as the silicates of iron and magnesium. The continents are made up of felsic rocks such as sodium, potassium and aluminum silicates. The mantle is composed of iron , nickel , silicates that are generally in solid state. The core is made up of iron and nickel mainly, although we can find materials such as lead and uranium.


The layers of the Earth are important because they are responsible for the formation of our continents . Two hundred and fifty million years ago, most of the land mass came together to form a super continent called Pangea . Through the years it had derived continental , which is the gradual movement and formation continents described by tectonics of plates .

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