Major Water Bodies on Earth
Define
Seas - Water bodies that are smaller than oceans are called seas. For example, Mediterranean sea
Marginal seas - Seas that are extensions of oceans and are partially surrounded by land.
Inland Seas - Seas that are completely surrounded by land without any outlet into the ocean.
Bay - A curved indentation of a sea or lake into the land with a wide opening
Gulf - A large inlet of a sea cutting deep into the land.
Hydrosphere - All the water bodies like oceans, seas, lakes and rivers taken together.
Lagoons - Shallow salt water bodies separated from the sea by a low sandbank or coral reef.
Lake - A small water body surrounded by land on all sides.
Oceans - Vast water bodies surrounding the continents.
Rivers - Water bodies that flow in a definite channel down the slope of the land towards a sea/lake.
Strait - a narrow stretch of water that joins two large water bodies and separates two land masses
Major water bodies
Pacific Ocean
Largest and deepest ocean
Mariana Trench is the deepest place on the earth
It is surrounded by North America and South America in the east and Australia and Asia in the west.
It is joined with the Arctic Ocean through the Bering Strait.
In the south it merges with the Atlantic and the Indian oceans.
Atlantic Ocean
Second largest ocean
It is shaped like the letter ‘S’
it is surrounded by North America and South America in the west
It is surrounded by Europe and Africa in the east.
In the north it stretches up to Arctic circle
In the south it merges with the Pacific and Indian oceans
Indian Ocean
Only ocean named after a country
It is shaped roughly triangular
Arabian sea and Bay of Bengal are its two northward extensions
To its east lies Australia
To its west lies Africa
It merges with Atlantic and Pacific oceans in the south
Arctic Ocean
It lies around the north pole
It extends southwards up to the Arctic Circle
North America Europe and Asia border it in the south
It merges with the Atlantic between Greenland and Scandinavia
It is linked with the Pacific Ocean through the Bering Strait
Most part of it remains covered with thick ice throughout the year
Antarctic Ocean
Also known as Southern ocean
It is an extension of Pacific, Indian and Atlantic Oceans
it's surrounds Antarctica
What makes up the hydrosphere?
All the water bodies like oceans, seas, rivers and lakes together make up the hydrosphere. It also includes the ice sheets in the polar and high mountain regions, underground water and water vapour in the air.
Name the oceans of the world in descending order of size
Pacific Ocean
Atlantic Ocean
Indian Ocean
Arctic Ocean and
Antarctic Ocean
What is the Southern ocean?
The continent of Antarctica is surrounded by a water body, which is actually an extension of the Pacific, Atlantic and Indian Ocean. It is known as the Southern Ocean.
Differentiate between marginal sea and inland sea. Give one example of each.
How are natural lakes formed?
Natural lakes are formed by earth movements, glacial activity, volcanic activity, erosional and depositional activities of the forces of nature.
Name the two largest freshwater lakes in the world.
Great Lakes ( Superior, Michigan, Huron, Erie, Ontario)
Lake Victoria
What is a river? Name two large rivers that flow through India.
Water bodies that flow naturally, usually in definite channels, moving down from mountains or hills towards a sea, lake or inland basin, are called rivers.
Two large rivers flowing through India are
Ganga and
Brahmaputra
Name the source and the mouth of the Amazon River. Which countries are drained by this river?
The source of the Amazon River lies in the Andes mountain and its mouth lies in the Atlantic Ocean.
Brazil, Peru, Bolivia, Ecuador, Colombia and Venezuela are drained by this river.
How is a bay different from a gulf? Give an example of each.
What is a lagoon? Give an example.
A lagoon is a shallow body of salt water, separated from the sea by a low sandbank or coral reef.
Lake Chilka in Odisha is a lagoon.
What is a strait? Give an example.
A strait is a narrow stretch of water that joins two large water bodies and separates two land masses. Example - The Bering Strait and the Strait of Gibraltar
What are the causes of water pollution?
The causes of water pollution are
The discharge of wastewater from industries
The discharge of untreated domestic sewage
runoff from agricultural fields
oil spills and
littering
Mention the characteristics of the Indian Ocean.
The Indian Ocean is the only ocean named after a country. It is shaped roughly triangular. It is bound in the north by the continent of Asia. India lies at the head of this ocean. The Arabian sea and the Bay of Bengal are its two northward extensions. To its east lies Australia and to its west lies Africa. It merges with Atlantic and Pacific oceans in the south.
How are oceans useful to us?
They are home to a great variety of marine life
They are enormous source of energy
They serve as means of transport
They are the source of clouds and thus bring rainfall
Describe the various methods of controlling water pollution.
The various methods of controlling water pollution are:
sewage treatment plants must be used to treat domestic sewage
waste water must be recycled
Industrial effluents should be treated before emptying into water bodies
use of chemical fertilisers and pesticides in agriculture should be controlled
Discuss the important features of the Pacific Ocean and the Atlantic Ocean
Pacific Ocean
Largest and deepest ocean
Mariana Trench of this ocean is the deepest place on the earth
It is surrounded by North America and South America in the east and Australia and Asia in the west.
It is joined with the Arctic Ocean through the Bering Strait.
In the south it merges with the Atlantic and the Indian oceans.
Atlantic Ocean
Second largest ocean
It is shaped like the letter ‘S’
It is surrounded by North America and South America in the west
It is surrounded by Europe and Africa in the east.
In the north it stretches up to Arctic circle
In the south it merges with the Pacific and Indian oceans
Explain the significance of lakes.
Lakes are of Great Value in a number of ways
They help us to regulate the flow of a river. during heavy rainfall, they prevent flooding and during the dry season, they help to maintain a regular flow of water.
They serve as a source of food and Minerals.
They moderate the climate of the surroundings.
They provide scenic beauty and recreation facilities, thereby helping to develop tourism.
The water of lakes can be used for irrigation navigation and for generating hydroelectricity.
‘Rivers are an important natural resource’. justify this statement.
Rivers are a prime natural resource.
They are essential for various human activities, therefore settlements have developed along river banks from ancient times.
They are used for irrigation and for generating hydroelectricity
They serve as a means of transport
They provide various species of fish
They enhance scenic beauty and provide recreation facilities, thereby promoting tourism
Most parts of the Arctic Ocean remain covered with thick eyes throughout the year. Why?
Extensive Glaciation and lower sea level cuts off the Arctic from other Oceans. Each year a thin layer of Arctic freezes over, forming sea ice.
Why are lakes and rivers important tourist attractions?
It is so because they provide scenic beauty and recreation facilities.
Why is there a scarcity of freshwater?
The contaminants in the water bodies harm the aquatic ecosystem and affect the quality of water, resulting in scarcity of fresh water.
Comments