Our Earth

Edu-Primes

8/17/2024

Transcript

00:00PLANET EARTH

00:07The earth is different from other planets.

00:11We know that the earth is the third planet in the solar system and that it receives sufficient

00:22amount of sunlight for life to exist.

00:28The earth is enveloped by a blanket of air known as the atmosphere.

00:37The atmosphere contains life-supporting gases such as nitrogen, oxygen and carbon dioxide.

00:49The major part of the earth's surface is covered with water.

00:55The presence of sunlight, air and water helps us to survive on earth.

01:05SHAPE OF THE EARTH

01:07In the ancient days, it was believed that the earth was flat.

01:14It was around the 15th century that Christopher Columbus and Ferdinand Magellan undertook

01:23many voyages to prove that the earth was round.

01:30People came to know that the earth was not flat but spherical.

01:38When we observe a ship sailing out to the horizon from the beach, we see the hull disappears

01:46first followed by the mast.

01:52This proves that the ship is going round rather than falling off a cliff.

02:00Now we know that the earth is spherical in shape but flat at the poles and bulging at

02:08the center.

02:12HORIZON

02:14It is an imaginary line where the sky appears to meet the land or sea.

02:23This is possible only if the shape of the earth is spherical or round.

02:33GLOBE

02:34Globe is a model that represents the earth and is spherical in shape.

02:42The word globe is derived from the Latin word globus, which means a round mass or sphere.

02:53A globe facilitates the study of the earth.

02:59It also helps to locate places on the earth.

03:05NORTH POLE

03:07It is the northernmost point on the earth.

03:12SOUTH POLE

03:14It is the southernmost point on the earth.

03:19AXIS

03:20The earth's axis is an imaginary line which passes through the center of the earth joining

03:27the north and south poles.

03:31In the picture, the earth's axis is represented by a dotted line.

03:39The earth moves around the axis which makes it possible for all parts of the earth to

03:46receive sunlight.

03:50This movement is known as rotation.

03:55The arrows represent the direction of the rotation of the earth around the axis.

04:04EQUATOR

04:06The equator is an imaginary line that divides the earth horizontally in two equal parts.

04:15It is halfway between the north pole and the south pole.

04:21The two equal parts are called the hemispheres.

04:27Hemi means half, sphere means round.

04:33The upper half is referred to as the north hemisphere and the lower half is referred

04:41to as the south hemisphere.

04:46CONTINENTS AND OCEANS

04:48The surface of the earth has vast continuous land masses called continents.

04:58The large deep continuous water bodies on the earth are called oceans.

05:07They cover 75% of the earth's surface.

05:14The water of oceans is saline.

05:19CONTINENTS OF THE WORLD

05:22There are seven continents on earth.

05:25They are Asia, Africa, Europe, North America, South America, Australia and Antarctica.

05:43ASIA

05:44Asia is the largest continent on earth.

05:49It occupies one third of the total land mass.

05:56AFRICA

05:57It is the second largest continent.

06:00It was called the dark continent for a long time as not much was known about it.

06:09EUROPE

06:11It is the second smallest continent and lies northwest to Asia.

06:19NORTH AMERICA

06:21It is the third largest continent.

06:24It is twice the size of Europe.

06:29SOUTH AMERICA

06:31It is the fourth largest continent.

06:35IT IS CONNECTED TO NORTH AMERICA BY A NARROW STRIP OF LAND CALLED ISTHMUS OF PANAMA.

06:44ANTARCTICA

06:46Antarctica is a cold, remote continent in the southern hemisphere.

06:52It is nearly twice the size of Australia.

06:59AUSTRALIA

07:00It is the smallest continent in terms of land area.

07:05It is also called the island continent.

07:11A CONTINENT CONSISTS OF MANY COUNTRIES.

07:15For example, India is a part of Asia.

07:20OTHER COUNTRIES LIKE PAKISTAN, CHINA, MYANMAR and NEPAL ARE ALSO A PART OF THE SAME CONTINENT.

07:35AUSTRALIA HOWEVER IS THE ONLY CONTINENT THAT IS ALSO A COUNTRY.

07:43OCEANS OF THE EARTH

07:45The different oceans on earth are Pacific Ocean.

07:51It is the largest and the deepest ocean.

07:55It lies between Asia and Australia in the west and the Americas in the east.

08:05ATLANTIC OCEAN

08:08It is the second largest ocean.

08:11It lies between Europe and Africa in the east and the Americas in the west.

08:21INDIAN OCEAN

08:24It is the third largest ocean.

08:27It lies between Africa and Australia.

08:32It is named after India which lies to the north of the ocean.

08:40BALTIC OCEAN

08:42It is the smallest ocean and lies in the north polar region.

08:50SOUTHERN OCEAN

08:52Is an extension of the Pacific, Atlantic and Indian Ocean.

08:59This ocean encircles the continent of Antarctica.

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