What are the layers of the Earth

What are the layers of the Earth

Advances in seismology, the study of the propagation of seismic waves inside the planet Earth, has helped us to know much more about the composition of our planet and the different parts of the Earth. Do you know what the structure of the Earth is? Do you want to know the layers of the geosphere?

If the answers to the previous questions are yes, you have come to the perfect article. In oneHOW we tell you what are the layers of the earth, including both its outermost layers and the internal structure of the Earth. Take a pencil and paper, because you are going to learn many characteristics and curiosities about the structure of our planet.

To know what the layers of the Earth are, let’s imagine that we cut the planet into two halves, so that we can see both its outer and inner parts. Thus, we would see that we can divide the planet Earth into three parts:

  • Atmosphere: it is the great layer of air that surrounds the planet and, therefore, the outermost layer of the Earth.
  • Hydrosphere: it is a large layer of water found on the earth’s surface.
  • geosphere: this is how we know the solid and rocky layer of the planet, that is, from the surface to the innermost part of the Earth.

Layers of the atmosphere

The atmosphere is the gaseous layer that surrounds the planet and, therefore, the outermost layer of the earth and the least dense. It is composed of a mixture of different gases that vary in quantity, depending on the pressure at different heights. The main ones are oxygen (21%) and nitrogen (78%), in addition to other minor gases such as argon, carbon dioxide and water vapor.

According to its pressure and composition, we differentiate different layers in the atmosphere:

  • Troposphere: it is the first layer of the atmosphere and ranges from the earth’s surface to 10-12 km, measured from sea level. Here air movements and other atmospheric phenomena take place, such as changes in temperature or the formation of clouds and rain.
  • Stratosphere: it is located between 10 km and 50 km in height and in it there are various gases that separate forming different strata, depending on their weight. The best known is the ozone layer, which has the function of protecting the Earth from the sun’s rays. In the stratosphere, the amount of oxygen and carbon dioxide is non-existent and the proportion of hydrogen increases.
  • Mesosphere: from 50 km to about 80 km in height is the mesosphere, a layer where temperatures plummet (down to -90ºC).
  • Thermosphere: between 90 km and 400 km in height is the thermosphere, a layer formed by ions (electrically charged atoms), making it an electrically conductive layer. The electromagnetic waves that allow radio and television transmissions are reflected in it. The temperatures of the thermosphere oscillate between -76ºC and 1,500ºC.
  • Exosphere: it is the last layer of the atmosphere and in it the gases are dispersed into outer space. It is located from the thermosphere up to about 580 km of altitude. It is contained in the magnetosphere that represents the Earth’s magnetic field and where cosmic dust is concentrated. Also, in the exosphere are artificial satellites.

If you want to know more, don’t miss this other article about What are the layers of the atmosphere.

Layers of the hydrosphere

The hydrosphere is the water layer surrounding the planet Earth. It is continuously in motion and its physical state changes following the water cycle, which helps transform the earth’s surface. This layer of water occupies three quarters of the Earth’s surface, being 97% salt water (seas and oceans) and only 3% fresh water (rivers, lakes, acoifers, clouds, etc.).

Layers of the geosphere

The geosphere is the layer of rocks that makes up our planet and is characterized by its enormous depth and high temperatures. According to its characteristics, we can differentiate several layers of the geosphere that form the internal structure of the Earth. They are as follows:

  • Earth crust: It is the outer layer of the Earth and has a depth that goes from the surface to approximately 70 km. Within the earth’s crust we find the oceanic crust, the thinnest part on which the ocean is situated; and the continental crust, the thickest.
  • Mantle: it is the thickest layer on earth, with a depth of up to 2,890km. The mantle is divided into two parts, the upper and the lower. It is formed by rocks that make it solid and, at the same time, ductile due to the high temperatures inside.
  • Nucleus It is the innermost part of the planet and is located in the center of the internal structure of the Earth. It is characterized by its high temperatures and its composition is still being studied today.

Although we know a lot about the Earth, there is also a lot to discover. It is a planet formed ago more than 4,500 million years. Without a doubt, it is a very special planet due to the large amount of life it houses. To get to know it better, let’s see its characteristics.

General characteristics

If we talk about the Earth, it is essential to know its general characteristics that make it a unique planet in the Solar System.

  • Volume: 1,083,206,916,846 km3
  • Minimum / maximum temperature: -88ºC / 58ºC

Situation

Earth is a planet that lies inside the solar system. The distance between the Sun and the Earth It is about 150 million kilometers from the Sun, which makes it occupy the third position in terms of proximity to the sun king.

Its location makes our planet orbit around the Sun, the star from which comes the light and heat that allow life to exist. In basic terms, the Earth experiences two types of movements:

  • Rotation: is the rotation around its axis in the counterclockwise direction. The rotation allows the achievement of the days after giving a complete turn on itself. Thus, each rotation lap is completed in 24 hours, that is, the duration of one day.
  • Translation: is the movement that the Earth makes around the sun in an elliptical orbit. Thanks to its 23.45º inclination, the seasons are possible: winter, spring, summer and autumn. When the planet has completely circled the Sun, it is understood as one year, which represents 365 days.

If you want to know more about the movements of our planet, take a look at this other article about How the planet Earth moves.

Temperature

As we have seen, the Earth has a privileged position, since it is close enough to the sun for its rays to heat the earth’s surface and, in turn, far enough to prevent the solar wind from dragging the planet out of its field. gravitational. In addition, the atmosphere controls the heat that enters the earth’s surface, making temperatures ideal for life.

However, due to the Earth’s tilt and translational motion, among other things, the Earth’s temperature varies depending on the area and the season. Although there are extreme temperatures of up to 58 ºC or -88 ºC, it is considered that average temperature is 15 ºC.

Habitability

Although the Earth was formed 4.5 billion years ago, it took 1,000 million years for the planet to become a suitable space for life. A) Yes, 3.5 billion years ago the first living beings appeared on the planet. But why is Earth the only habitable planet?

When it originated, the Earth was a kind of fireball formed from meteorites that were grouping together little by little, so life on our planet was not possible. However, the lava and gases that covered the earth’s surface formed the atmosphere and the hydrosphere. Thus, the surface cooled and solidified. This combined with solar energy and other characteristics allowed the appearance of the first living beings.

The Earth is a living planet, in continuous movement and change, from its formation until today. These changes can be internal, through the manifestations that originate in its interior, such as the explosion of volcanoes, earthquakes or the displacement of the lithospheric plates that move the continents. They can also be external changes, such as rain or wind, that help modify its relief.

Now that you know what the layers of the Earth are and their main characteristics, learn What if the Earth stopped spinning or watch this video to see What the Earth looks like from space.