The internal structure of the Earth, that is, the entire composition of the planet formed by the surface and everything below it is formed by various shapes, temperatures, aspects and compositions chemical. For a better understanding of how the planet is structured, a classification was elaborated that gave rise to what we understand today by layers of the Earth.
Altogether, the planet has three main layers and two discontinuities, which are the structures found between one layer and another. Check out the following scheme:
Explanatory scheme of the Earth's layers
The first layer of the Earth is the Earth's crust. It is the smallest structure on the planet, but it is the most important for human activities. It is fundamentally composed of light rocks, having as predominant minerals silicon, aluminum and magnesium. In continental zones, it varies from 20 to 70 km in thickness, measurements that decrease in oceanic zones, where the variation is from 5 to 15 km.
Below the earth's crust is the
Mohorovicic Discontinuity or simply Moho. In it, seismic variations are usually faster and more fluid in relation to its external composition.The second layer of the Earth is the cloak. It has depths ranging from 30 km below the surface to 2900 km, in addition to temperatures interiors that reach 2,000°C, which allows the melting of the rocks, transforming them into magma. In the inner mantle, the material is more liquid, given that the temperatures are higher; in the outer mantle, the magmatic material is more pasty.
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Just below the mantle is another discontinuity, that of Wiechert-Gutenberg, also known only as Gutenberg discontinuity. It is completely in a liquid state and has higher temperatures than the mantle.
The third and last of the Earth's layers is the Core. Its composition is not known exactly, but there is strong evidence that it is formed by an alloy of iron and nickel, which may also involve another chemical element as yet unknown. The outer core is in a liquid state and the inner core is solid due to the influence of the planet's internal pressure on it.
It is now known that the Earth's inner core rotates at a speed greater than the planet's own rotational motion. This is because, as the outer core is liquid, the inner core is immersed in this veritable “chamber” of molten magma, which insulates it from the remaining layers. The fact that it rotated at great speeds indicates that the planet also rotated faster in remote times.
By Rodolfo Alves Pena
Graduated in Geography
Would you like to reference this text in a school or academic work? Look:
PENA, Rodolfo F. Alves. "Layers of the Earth"; Brazil School. Available in: https://brasilescola.uol.com.br/geografia/camadas-terra.htm. Accessed on June 27, 2021.
