Test: Major Domains Of The Earth

• The crust is the rocky outer part of the Earth.
• It is made up of the brittle crust and the top part of the upper mantle.
• The crust is the coolest and most rigid part of the Earth.

• The hydrosphere is the combined mass of water found on, under, and above the surface of the earth.
• It has been estimated that there are 1386 million cubic kilometres of water on earth.
• This includes water in liquid and frozen forms in groundwater, oceans, lakes and streams approximately 75% of Earth’s surface, an area of some 361 million square kilometres is covered by ocean.

• There are four named ocean basins: the Atlantic, Pacific, Indian, and Arctic.
• However, most countries - including the United States - now recognize the Southern (Antarctic) as the fifth ocean basin. The Pacific, Atlantic, and Indian are the most commonly known.

• The seven-continent model is probably the most widely taught. 
• The continents are, from largest to smallest: Asia, Africa, North America, South America, Antarctica, Europe, and Australia.

• The atmosphere is composed mainly of nitrogen and oxygen, which make up about 99 per cent of clean, dry air.
• Nitrogen 78 per cent, oxygen 21 per cent and other gases like carbondioxide, argon and others comprise 1 per cent by volume. 

• The only ocean named after a country is the Indian Ocean.
• Indian ocean is named after the country 'India' and is the third largest ocean in the world.
• The area occupied by the ocean is 20% of the earth's total surface area.
• The Indian Ocean is, both geographically and politically, the most complex ocean of the world.
• The shape of ocean is almost triangular. In the north, it is bound by Asia, in the west by Africa and in the east by Australia.

These are the four major domains of the earth

1. Lithospehere
2. Hydrosphere
3. Atmosphere
4. Biosphere

Detailed Solution:

• The Lithosphere is called the solid portion of the earth on which we live. It comprises the thin layers of soil that contain nutrient elements that sustain organisms and the rocks of the earth’s crust.
• The Hydrosphere is a very big area of the earth’s surface that is covered by water. It comprises water in all its forms, that is, water vapor, ice, and water. As for running water in rivers and oceans and in underground water, lakes, ice in glaciers, and the water vapor in the atmosphere, all comprise the hydrosphere. The earth is called the blue planet. More than 97%97% of the Earth’s water is found in the oceans and thus is too salty for human use. A large proportion of the rest of the water is in the form of glaciers and ice sheets or under the ground and a very small percentage is available as freshwater for human use. Hence, we face a shortage of water despite being a ‘blue planet’.
• The Atmosphere is the gaseous layers that surround the earth, where oxygen, nitrogen, carbon dioxide, and other gases are found. This thin blanket of air is an integral aspect of the planet. It protects us from the harmful effects of the sun’s rays and provides us with the air we breathe. The atmosphere extends up to a height of about 1,600 kilometers and is divided into five layers based on its temperature, composition, and other properties. These layers are called the troposphere, the stratosphere, the mesosphere, the thermosphere, and the exosphere.
• The Biosphere is the narrow zone that contains all forms of life where we find land, water, and air together. This is the zone in which life is unique to this planet. The organisms in the biosphere may be divided into the plant kingdom and the animal kingdom.

An atmosphere is a sheet of gases that surround material body or a planet. It is controlled by the gravity of that body. Argon, oxygen and nitrogen form the three main constitutions of the atmosphere.

The greatest depth of 11,022 metres is at Mariana Trench in the Pacific Ocean.

• By area, Asia is the largest continent at 44,391,162 square km.
• It is also the largest by population with more than 4 billion people.
• There is quite a bit of debate as to how many continents there are.
• Some areas of the world combine Asia and Europe into one continent called Eurasia.