Atmosphere, Hydrosphere And Biosphere

Last class we discussed about the structure of the earth, and we emphasizes on Lithosphere (crust), Mesosphere (mantle) and Barysphere [the inner and the outer core] our today’s topic is on Atmosphere, Hydrosphere And Biosphere. So let not waste any time, let start with Atmosphere.

Atmosphere, Hydrosphere And Biosphere


The Atmosphere is composed of a mixture of gases which forms an envelope around the earth.

The atmosphere contains 78% of nitrogen, 21% of oxygen, 0.03% of carbon (iv) oxide and 0.97% of inert, noble or rare gases. Let briefly talk a little bit about the composition of the atmosphere.

Composition Of The Atmosphere

The atmosphere a.k.a Air consist of permanent, variable and inert gases.

Permanent Gases : Nitrogen → 78.09%
Oxygen → 20.95%.

Variable Gases : Water vapour → 0.2 to 0.4%
Carbondioxide → 0.03%
Ozone → 0.00006%

Note : carbon (iv) oxide is the modern name for carbondioxide.

Inert Gases : Argon → 0.03%

helium, neon, krypton → Trace.

Now let talk about the importance of atmosphere. The first important that should first come to your mind is we breathe it in

Importance Of Atmosphere

a] Atmosphere provides oxygen for breathing in animals and also for plants to carry out respiration.

b] It acts as an habitat to some living organisms.

c] Atmosphere contains the ozone layers which acts as a protective cover for living organisms against the burning effect of ultra violent rays of the sun.

d] It also provides nitrogen for plants (protein synthesis).

e] Atmosphere serves as a meridian of communication e.g air routes.

f] It provides carbondioxide for photosynthesise plants.

g] It also provides oxygen for combustion or burning.

Brief : As we have already mention above that, Nitrogen, Oxygen, Carbondioxide, and rare gaes is the constituent of the atmosphere: it is the Nitrogen in the air that reduces the rate of combustion. Meaning that, the rate of combustion or burning will be high if there is no nitrogen in the atmosphere.

Important Note

They ask this question that, which element cannot be present in the air, Well it is hydrogen
REASON : if hydrogen is present in the atmosphere, then the earth will be full of water: because the hydrogen will react with the oxygen in the air to form water. That means that, it is possible to have other elements present in the atmosphere: for example, fluorine is the most reactive non-metal (it react with every element), meaning that it is possible but hydrogen can never be. → I’ll explain better in chemistry class. I think that’s all on Atmosphere, now let talk about Hydrosphere, as we already know today’s topic as Atmosphere, Hydrosphere and Biosphere.


Hydrosphere is the water masses of the earth crust which include rivers, oceans, seas, lake, and glaciers underground water in the lower atmosphere. Hydrosphere, is the liquid portion of the earth crust and it occupies about 70% of the total earth crust.

Important Note : hydrosphere is the layer of the earth that holds water in both solid and gaseous form.

Importance Of Hydrosphere

a] As mention above that hydrosphere is the liquid portion of the earth crust, hence, it provides water for both domestic and industrial uses.

b] Hydrosphere serve as source of employment for the people dwelling in the riverine areas, e.g fishermen.

c] It serve as a means of transportation. #sailing#

d] It is use to generate electricity such as hydroelectric power, e.g kanji dam in Nigeria, Itaipu Dam in Brazil, Three Gorges Dam in China {China has the largest hydrostatic capacity of 22,500 MW}

e] It is used for irrigation and dams.

f] Hydrosphere also encourages tourism.
In addition, it also serve as a recreation center.


Biosphere from the name Bio. Biosphere is the biological active part of the earth which supports life and consists of plants, animals and micro-organisms.
Biosphere includes the lower atmosphere and the upper lithosphere.

Characteristics Of Biosphere

1) It supports life.

2) Biosphere is a narrow zone where complex biological and chemical activities occurs.

3) It consists of both living and non living organisms such as plants, animals and micro-organisms.

Importance Of Biosphere

a] Source Of Food : Plants in the biosphere server as source of food.

b] Source Of Raw Materials : the plants present in biosphere provides raw materials such as cotton, wool, etc. In addition, biosphere also provides materials such as timber.

c] Source Of Energy : It provides source of energy such as fire wood.

d] Purification Of The Atmosphere : biosphere aids the balancing purification of atmospheric gases such as Oxygen during photosynthesis and carbondioxide during respiration.

Those are the importance of the three earth layers, Atmosphere, Hydrosphere and Biosphere. Now let discuss about the interaction between and within this layers and lithosphere.

Interaction Between And Within Lithosphere, Atmosphere, Hydrosphere And Biosphere

Interaction Within The Lithosphere

a] The rocks disintegrate to form the soil.

b] The rocks are transformed into some very useful materials such as granite. And beneath this rocks lies valuable materials such as Gold, Coal, etc.

Interaction Within The Atmosphere

Atmosphere → Biosphere

a] Water vapour combines to form cloud which later fall in form of rain.

b] Carbondioxide is taken-in by plants to release oxygen during photosynthesis.

c] Oxygen is taken-in by plants and animals to release carbondioxide.

Brief : b and c is one of the dependant relationship between plants and animals : animals provides plants with carbondioxide to carry out photosynthesis and plants provide animals with oxygen to breath. Get more explanation in the biology class.

Interaction Within The Hydrosphere

Hydrosphere → Biosphere

a] Water from the seas and oceans evaporates to form clouds and rainfall.

b] Water from the rivers, streams and rainfall are drained into seas and oceans.

Interaction Within The Biosphere

a] The Animals depend on plants for their food.

b] The decomposition of animals provide manure to the plants.

c] The plants provide oxygen for the animals during photosynthesis.

d] The animals provide carbondioxide for the plants during respiration

e] The Micro-organisms in the soil promote plants growth.

Those are the individual interaction between and within lithosphere, Atmosphere, Hydrosphere and Biosphere. Now let talk about the overall interaction between the four zones.

Interaction Between The Four Zones

a] Plants in biosphere derived their nutrients from the soil (I.e lithosphere).

b] Some gases such as carbondioxide and oxygen are stable in the environment through the process of photosynthesis.

c] During photosynthesis of plants that is growing on the soil (lithosphere), a sunlight from the atmosphere is needed.

d] Water in the hydrosphere is evaporated and converted into water vapour in the atmosphere.

And we come to the end of our topic, “Atmosphere, Hydrosphere and Biosphere” our next topic in Geography will be rocks, where we be talking about Igneous, Sedimentary and metamorphic rocks. So until then, GOD bless me. Please don’t forget to hit the sharing button and also write a comment. Thank you.

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