We explain what the geosphere is and what its structure is like. Also, how this set of layers is composed and its importance.
What is the geosphere?
In the natural sciences, the geosphere is called the geosphere. set of layers that make up the solid part of the Earth. Together with the hydrosphere (aquatic part), the atmosphere (gaseous part) and the biosphere (set of living beings), they make up the parts into which our planet can be analytically divided.
Just like other terrestrial planets (solid surface), The Earth is made up of rocky materials of different nature and that present different dynamics among themselves, many of which date back to the first geological periods or were formed during turbulent stages of volcanic activity. Many of the oldest known rocks on the planet date back more than 4.4 billion years.
The study of the geosphere by geologists and other specialists, it is carried out through the experimental review of soils, especially in places where terrain features reveal strata to the surface that would normally remain hidden.
Likewise, many observations are theoretical or derived from calculation: the mass and volume of the Earth are not measurable directly, but can be measured through other calculable variables, such as gravity, or the reverberation of seismic waves.
See also: Planet
Structure and composition of the geosphere
The structure of the geosphere is studied from two different perspectives: from the chemical point of view and from the geological point of view.
From the point of view of its chemical composition, the geosphere comprises three layers: crust, mantle and core.
- Crust (from 0 to 35 km depth). It is the superficial rock stratum on which we live, whose relatively thin thickness includes an average density of 3.0 g/cm3. This includes seabeds and deep depressions. It is made up mainly of mafic rocks (iron and magnesium silicates), felsic rocks (sodium, potassium and aluminum silicates).
- Mantle (from 35 to 2890 km deep). It is the thickest layer of all, composed of siliceous rocks, with a higher iron content than the crust. As we enter the mantle, the temperatures and pressures become colossal, achieving a state of semi-solidity in the rock that composes it, capable of allowing the movement of the tectonic plates and being responsible for tremors and earthquakes. . Due to the pressure, the upper part of the mantle appears less viscous and more mobile than the lower part, varying between 1021 and 1024 Pa.s in magnitude.
- Core (from 2890 to 6371 km depth). The innermost portion of the planet, where the densest materials are found (Earth is the densest planet in the Solar System). The core is further divided into two strata: outer core (from 2890 to 5150 km deep) and inner core (from 5150 to 6371 km deep), and is composed mostly of iron (80%) and nickel. , while elements such as lead and uranium are in short supply.
Instead, from a geological point of view, the geosphere is divided into:
- Lithosphere (from 0 to 100 km depth). This is the solid portion of the geosphere, where the solid rocks are and which corresponds to the crust and the superficial portion of the mantle. It is fragmented into a series of tectonic or lithospheric plates, on whose edges seismic and volcanic phenomena and orogenesis take place.
- Asthenosphere (100 to 400 km deep). Composed of ductile materials in a semi-solid to solid state, corresponding to the Earth's mantle. The very slow movements that make up continental drift take place there; but as it gets closer to the core it loses its properties and becomes rigid like the lower mantle.
- Core (from 2890 to 6371 km depth). Located at the end of the lower mantle, the core or endosphere is the terrestrial geological portion that comprises the largest amount of mass on the planet (60% of the total). Its radius is greater than that of the planet Mars (about 3,500 km) and it has enormous pressure and temperatures greater than 6,700 °C. Composed mainly of iron and nickel, it is divided into an outer core of liquid nature and an inner core of solid nature.
Importance of the geosphere
The geosphere It is the oldest portion of our planet and where all its secrets are locked.. Geology scholars try to discover the various processes involved in its formation, which also shed light on the formation of the rest of the stars in the Solar System and, therefore, the origin of the universe. The same occurs with seismology, a science that tries to understand the nature of geological and tectonic movements to prevent eventual earthquakes and prevent them from being so destructive for humanity.
On the other hand, the study of the geosphere goes hand in hand with the understanding of the materials that we can find on our planet, which has important repercussions on various industries, engineering and international trade, among other vital areas.
References
- “Geosphere or geosphere” in Online Teacher.
- “Internal structure of the Earth” in Wikipedia, the Free Encyclopedia.
