Domains of the Earth
Earth is the planet in our solar system that has the capability to provide life. The surface of the earth is a zone where three main components of the environment meet, overlap as well as interact.
There are four major domains of the Earth as follows- lithosphere, atmosphere, hydrosphere, and the biosphere. The atmosphere is further divided into four layers based on composition, temperature, and other properties that are the troposphere, stratosphere, mesosphere, thermosphere, and exosphere.
There are Two Main Divisions of the Surface of the Earth
Continents: Continents are large landmasses.
The Highest Mountain Peak on this planet is Mount Everest.
Ocean Basins: Oceans are huge water bodies.
Mariana Trench is the deepest Oceanic trench on this Earth which derives its name from the nearby Mariana Islands.
The Four Major Domains of the Earth
The four major domains of the earth interact with each other as well as affect each other in some way or the other.
Lithosphere: The solid portion of this planet is called the Lithosphere.
Atmosphere: The gaseous layers that surround the earth are called the atmosphere.
Hydrosphere: Water covers a very big area of the earth’s surface that is called the Hydrosphere.
Biosphere: Biosphere is the zone where land, water, and air together are found.
Lithosphere - The Domain of Land
The very outermost portion of the Earth which consists of the Upper Mantle and also the Crust of the Earth is known as the Lithosphere.
Lithosphere has very rigid mechanical properties. The uppermost part of the lithosphere is called the pedosphere. The tectonic plates are a subdivision of the Lithosphere. The major changes in these tectonic plates had created a total of seven continents on the planet earth. These continents are - Asia, America, Europe, Africa, Antarctica and Australia. Asia is the largest continent and the smallest continent is Australia.
Hydrosphere - The Domain of Water
The domain of water is called the hydrosphere. It comprises different sources of water and also various types of water bodies like rivers, lakes, seas, oceans, etc. Water is very essential for all living organisms in the world.
The hydrosphere comprises water on earth in Oceans, Seas, Rivers, Lakes, and even in frozen forms where 2.5% is freshwater and in this 2.5%; approximately 69% is in snow and ice form. The other 97.5% of Earth’s water is salt water and 71% of the surface of the Earth is covered by oceans. Earth got a total of seven oceans namely - the Arctic, North Atlantic, South Atlantic, North Pacific, South Pacific, Indian, and Southern oceans
Atmosphere - The Domain of Air
The atmosphere is divided into five layers and they are:
Troposphere (0 - 12 km): It is the lowermost layer of the earth’s atmosphere, and extends to an average of 12 km from the surface of the earth. Nearly all the water vapour and moisture found in the atmosphere lie in this section - the “troposphere”.
Stratosphere (12 - 50 km): It is the second-lowest section of the atmosphere, just after the troposphere, and is separated by the troposphere via the tropopause. The ozone layer of the earth is also included in this layer, the Ozone layer is filled with a high concentration of Ozone gas.
Mesosphere (50 - 85 km): Mesosphere is in the middle of the other atmospheric layers. In the mesosphere, the temperature dropped down by the increase in the altitude, this trend will then be followed by all the layers above it. It can be said to be one of the coldest places on the planet earth, with a temperature of - 85 °C (- 120 °F; 190 K).
Thermosphere (80 km to 500 - 1000 km): This layer is the second-highest in the five atmospheric layers. It expands from the mesopause (which separates it from the mesosphere) all the way above to the thermopause (which cuts it from the exosphere). This is sometimes referred to as the exobase, as it lies just under the exosphere.
Exosphere (700 km to ~10,000 km): It is the outermost layer of the earth. It extends to 10,000 km outside the earth’s surface, after that it disappears in the solar wind. The main composition of this layer consists of extremely low densities of hydrogen and helium, some other molecules like traces of Nitrogen gas are also present in this layer.
About 99 per cent of the atmosphere is composed of nitrogen and oxygen where Nitrogen is 78 percent, oxygen is 21 per cent, and other gases comprise 1 per cent.
Biosphere – The Domain of Life
The biosphere is the zone of contact between land, water, and air. It is the zone where life exists and that is what makes this planet unique.
The organisms in the biosphere are divided into:
FAQs on What are the Domains of the Earth
1. Write a Short Note on Oceans.
Oceans are the major part of the hydrosphere. The Five Major Oceans are:
Pacific Ocean: It is circular in shape which is surrounded by Asia, Australia, North and South Americas.
Atlantic Ocean: It is the second-largest ocean on this planet.
Indian Ocean: It is the only ocean named after a country, that is, India and it is almost triangular in shape.
Southern Ocean: This ocean surrounds the continent of Antarctica
Arctic Ocean: this ocean is located within the Arctic Circle and surrounds the North Pole.
2. Write a Short Note on Continents.
There are seven major continents on this planet that are separated by very large water bodies.
Asia is the largest continent on this planet which occupies 30 per cent of the landmass and is also the most populous continent on earth.
To the south lies the Indian Ocean, to its North lies the Arctic Ocean, and to the East of this continent lies the Pacific Ocean.
The Suez Canal separates Asia and Africa whereas the Black Sea and the Caspian Sea separate Asia and Europe
The 2nd largest continent on Earth is Africa covers 20% of the Earth’s total land area
The Equator, Tropic of Cancer, as well as the Tropic of Capricorn passes through this continent.
The world’s longest river Nile is in Africa that has two major tributaries, passing through eleven countries.
The largest hot desert is the Sahara Desert which is in Africa.
It extends from the Atlantic Ocean in the West, to the Red Sea located in the East and covers a large part of the African Continent.
The Mediterranean Sea lies to the North of the Sahara Desert.
Europe is the sixth-largest continent occupying approximately two per cent of the Earth’s surface.
Russia is the largest country which half falls in the European continent.
Europe is the origin of western civilization.
Atlantic Currents have the biggest influence on this Continent.
To the south lies the Atlantic Ocean, to the North of Europe lies the Arctic Ocean, and to the West lies the Atlantic Ocean.
4. North America
North America is the 3rd largest continent in the world that lies completely in the Northern and Western Hemispheres.
The Isthmus of Panama is a narrow strip that links two continents namely North America and South America.
This continent is surrounded by three major oceans namely the Atlantic Ocean, the Pacific Ocean, and the Arctic Ocean.
5. South America
There are a total of twelve Sovereign States in South America and it is the 4th largest continent.
It is located in the Southern Hemisphere, to the East lies the Atlantic Ocean, and the Pacific Ocean is located to the West of this continent.
Brazil is the most populous country on this continent.
Australia is the smallest continent that lies totally in the Southern Hemisphere and is surrounded by the oceans and seas.
It is also called an island continent.
Antarctica is a huge continent that lies completely in the Southern Hemisphere.
The South Pole lies almost at the centre of Antarctica and is permanently covered with thick ice sheets.
3. Explain the five layers of the Atmosphere - the domain of Air?
The Domain of Air also known as the Atmosphere is divided into a total of five layers. These five layers are explained here as follows -
Troposphere: The lowest layer of the atmosphere is known as the troposphere and extends from the surface of the earth to the height of 12km.
Stratosphere: Stratosphere is the second-lowest layer of the atmosphere just after the troposphere. It extends from 12 km to 50- 55 km from the surface of the earth.
Mesosphere: Mesosphere lies above the stratosphere and below the thermosphere, it lies between the range of 50 km to 80- 85 km from the surface of the earth
Thermosphere: Second-highest layer of Earth's atmosphere is called the Thermosphere and it extends to 500 - 1000 km from the surface of the earth.
Exosphere: It is the outermost layer of the earth’s atmosphere.
4. What is the composition of the Atmosphere?
The three major constituents of Earth's atmosphere are nitrogen, oxygen, and argon, the amount of all other elements are negligible. With Nitrogen gas constituting the largest chunk of the atmosphere, nearly around 78.08%, while Oxygen and Argon consist of 20.9% and 0.9% of the atmosphere respectively. Some might be surprised by this but the noble gas argon is included more in the atmosphere than carbon dioxide, carbon dioxide (CO2) consists of only 0.04%. Some other gases that are present in enough quantities are Noen, helium and methane and krypton.
5. What is the Largest and smallest continent in the Lithosphere in terms of land and population?
The domain of the land - Lithosphere consists of a whole seven continents. These seven continents are - Asia, America, Europe, Africa, Antarctica and Australia.
In terms of Landmass
Continent Asia is the largest existing landmass, hence it is the largest continent in terms of the landmass in Asia.
Australia is considered the smallest continent in terms of landmass, It was earlier considered as an island rather than a continent when it was discovered.
In terms of Population
Asia again tops the list with 59.54% of the total population living inside these single continents
Antarctica has the lowest population due to the harsh weather conditions there.
6. How can I download reading material from Vedantu?
Accessing material from Vedantu is extremely easy and student-friendly. Students have to simply visit the website of Vedantu and create an account. Once you have created the account you can simply explore the subjects and chapters that you are looking for. Click on the download button available on the website on Vedantu to download the reading material in PDF format. You can also access all the resources by downloading the Vedantu app from the play store.