The Natural components of the Earth Are those elements that are present in the environment and whose formation does not depend on the intervention of human beings.
These elements are contemplated in the three main systems that make up the Earth, the atmosphere , Which is its gaseous envelope, the hydrosphere, the surface coating of water and the Lithosphere Which is solid earth.
Of all the planets in the solar system, Earth stands out because of the presence of water. When viewed from space, the first notable feature of the planet is its blue color.
This color comes from the oceans that cover more than 70% of its surface. No other planet in the solar system has water on the surface.
The next feature that stands out are scattered clouds that move around. These clouds indicate that the Earth is surrounded by an atmosphere containing gases and water vapor. Beneath the clouds, the earth's surface is also interesting because it shows signs of geological processes that form mountains.
Due to the force of gravity the heavier components, such as solids and liquids are arranged in the center of the Earth, while the outermost layer is formed by light gases.
Following is the natural composition of the Earth evaluating the elements present in solid, liquid and gaseous state in each of the systems.
Natural elements of planet Earth
1- The atmosphere
It is a relatively fine gaseous envelope, composed mainly of nitrogen (N2) and oxygen (O2), with small amounts of other gases such as water vapor (H2O) and carbon dioxide (CO2). Inside the atmosphere there are clouds of liquid water and ice crystals.
Although the atmosphere extends upwards several hundred kilometers, its density decreases progressively with the increase of the altitude.
Almost 99% of the atmosphere is about 30 km (about 19 miles) from the surface of the Earth (see Figure 1 ). In fact, if the Earth were reduced to the size of a large beach ball, its habitable environment would be thinner than a piece of paper.
Figure 1. The Earth's atmosphere seen from space. The atmosphere is the thin blue-white region along the Earth.
The thin blanket of air constantly protects the surface and its inhabitants from the dangerous ultraviolet radiation of the sun, as well as from the material of interplanetary space.
There is no upper boundary defined for the atmosphere, rather, it becomes thinner and thinner and eventually merges with the empty space, which surrounds all the planets.
Table 1 shows the different gases present in a volume of air near the surface of the Earth. Note that molecular nitrogen (N2) occupies approximately 78% and molecular oxygen (02) about 21% of the total volume of dry air.
Table 1. Composition of the atmosphere near the Earth's surface. (*) For CO2, 405 parts per million mean that out of every million air molecules, 405 are CO2 molecules. (**) The values of stratospheric altitudes between 11 km and 50 km are 5 and 12 ppm.
If all other gases are eliminated, these percentages of nitrogen and oxygen remain fairly constant up to an elevation of about 80 km (or 50 miles).
The hydrosphere
It is the combination of all free water on Earth that is not chemically and / or physically confined within the minerals of the Earth crust .
The hydrosphere occupies most of the Earth's surface, that is, more than 75% of the total area of the planet. The volume of the hydrosphere is 1.4 trillion cubic kilometers.
Oceans and seas
The oceans and seas form the greater part of the hydrosphere. They contain 1.37 x 109 cubic kilometers of water or about 94% of the total volume of the hydrosphere.
The storage of heat in the oceans and seas is large and controls the rate of energy on the surface of the Earth, producing the necessary conditions for life.
Underground water
Groundwater is the second largest component of the hydrosphere, its volume is approximately 0.6 x 109 cubic kilometers, or 4% of the total mass of the hydrosphere.
The intensive water exchange zone extends to a depth of 0.3 to 0.5 km, where groundwater is present as moisture in the soil and subsoil.
The slower water exchange zone extends more than 1.5 to 2 km from where it is difficult to interchange between surface and groundwater.
Snow and ice
Snow and ice accumulation follows groundwater by volume. Most of the ice is found in glaciers and is approximately 2.4 x 107 cubic kilometers, of which over 90% is concentrated in Antarctic glaciers.
Minor components
Portions of the other components of the hydrosphere, in addition to the three above, are small and can be considered as"minor components".
These components include water from rivers, lakes and swamps, soil moisture and water vapor in the atmosphere.
River water is the most important for human life because it provides most of the fresh water needed for survival. The waters of the hydrosphere are interrelated not only by their origin, but by the water cycle.
In this process all the parts of the hydrosphere are united by the main dynamic forces that cause the movement, that is, the gravitational force and the solar energy .
Table 2. Volume of water in the components of the hydrosphere. * Includes about 5,000 km3 of water in the reservoirs.
The lithosphere
It is the solid and rigid outer layer of our planet. Includes bark, mantle and core (exterior and interior).
Cortex
It is the thinnest exterior of the Earth where we live. The bark varies from about 5km thick (at the bottom of the ocean) to about 70km thick (continental crust). The continental crust consists of rocks consisting mainly of silica and an alumina called"sial".
Mantle
It is much thicker than the bark with almost 3,000km of depth. It is composed of slightly different silicate rocks consisting of magnesium and iron.
External nucleus
It is made of iron and nickel and is very hot (4,400 at approximately 5,000 ° C). It is so hot that iron and nickel metals are liquid.
The outer core is very important because it creates a magnetic field that creates a protective barrier around the Earth that protects us from the damaging solar wind.
Internal core
It is composed of iron and nickel, just like the outer core, yet it is so deep inside the Earth that it is under immense pressure.
It is the hottest part of the Earth, with a temperature above 5,000 ° C, it is almost as hot as the surface of the sun.
Figure 2: structure of the lithosphere.
The lithosphere contains rocks, minerals and soils. It consists of more than 100 chemical elements, but most of them are little known.
Eight elements constitute approximately 99% of the total volume of the lithosphere: oxygen (O), silicon (Si), aluminum (Al), iron (Fe), calcium (Ca), sodium (Na), potassium (Mg).
Table 3. Composition of the Earth's crust.
In the earth's crust, these elements generally form crystalline solid compounds of defined composition that are known as minerals.
Chemically, the minerals can be sulfides, oxides and hydroxides, halides, carbonates, nitrates, borates, sulfates, phosphates and silicates.
Most of the rock-forming minerals are aluminosilicates of calcium (Ca), magnesium (Mg), sodium (Na) and potassium (K). Rocks can be igneous, sedimentary and metamorphic.
Igneous rocks are formed by solidification of magma or lava, sedimentary rocks are formed by lithification of sediments or by consolidation of plant and animal remains, and metamorphic rocks are formed from preexisting rocks by change of temperature and pressure in the solid state.
By the action of natural forces on geological time, rocks and minerals disintegrate and decompose into new minerals and new compounds such as salts, Acids , bases And soluble substances. These processes are collectively known as weathering.
References
- 3 Main Components of Biosphere. Retrieved from: biologydiscussion.com.
- Ahrens, D. and Henson, R. (2014). Essentials of Meteorology: An Invitation to the Atmosphere . Stamford, Cengage Learning.
- Allan B. Cobb (2.009). Earth Chemistry. Langhorne, Chelsea House Publishers.
- Arnold, K. Sciencing: What Four Elements Make Up Almost 90% of the Earth? Retrieved from: sciencing.com.
- Choi, C. (2014). Space.com: Planet Earth: Facts About Its Orbit, Atmosphere & Size. Retrieved from: space.com.
- Composition of the Earth. Retrieved from: ducksters.com.
- Osman, K. (2013). Soils: Principles, Properties and Management . Netherlands, Springer Netherlands.
- Planet Earth. Retrieved from: uwgb.edu.
- I. (2009). Hydrological Cycle - Volume I. Encyclopedia of life support systems . Paris, Eolss Publishers / UNESCO.