Four Spheres of Earth

Four Spheres of Earth


Lithosphere

                                The lithosphere is the solid, rocky crust covering entire planet. This crust is inorganic and is composed of minerals. It covers the entire surface of the earth. The lithosphere is also called as geosphere.

Hydrosphere

                        The hydrosphere is composed of all of the water on or near the earth. This includes the oceans, rivers, lakes and even the moisture in the air. Ninety seven percent of the earth’s water is in the oceans. The remaining three percent is fresh water; three quarter of the fresh water is solid and exists in ice sheets.

Biosphere

                  The biosphere is made up of the parts of Earth where life exists. The biosphere extends from the deepest root systems of trees, to the dark environment of ocean trenches, to lush rain forests and high mountains.  The biosphere has existed for about 3.5 billion years.

Atmosphere

                                The atmosphere is the body of air which surrounds our planet. This gaseous envelope is most dense at sea level and rapidly decreases with increasing altitude. It is an important geological agent. It acts as a thermal blanket, captures heat and supply snow and rain water.
The air of our planet is about 78% nitrogen and about 21% oxygen; the small amount remaining is composed of carbon dioxide and other gases such as neon, helium, krypton, xenon, water vapors, dust particles and hydrocarbons etc.
Earth’s cycles and spheres are interconnected. All four spheres can be and often are present in a single location. The importance of soil as a natural body derives in large part from its role as an interface between above four spheres of earth.
The interface where the worlds of rock (lithosphere), air (atmosphere), water (hydrosphere) and life (biosphere) meet is termed as Pedosphere or soil.
For instance, a piece of soil will of course have mineral material from the lithosphere. Additionally, there will be elements of the hydrosphere present as moisture within the soil, the biosphere as insects and plants even the atmosphere as pocket of air between soil pieces.






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