Page 8 - SST Class 05

In a similar manner, the sunlight falls direct in the middle of the earth and is slanting
on the sides. That is, the sun shines direct over the areas around the Equator. So, it is
very hot in the middle and due to slanting sunlight on the sides, it is very cold near the
poles.

On this basis, we can divide the earth into three heat zones : North Pole

1. Very Hot Zone : The area around the Equator, within the Arctic Circle VERY C OL D Z O N E
two tropics (Tropic of Cancer and Tropic of Capricorn) MODERATE ZONE
receives direct sunlight. So, it is the hottest area on the earth. o r T p ic f o C a n c r e
AXIS OF THE EARTH
2. Very Cold Zone : The areas around the two poles, within VERY HOT ZONE Equator
circles, receive very slanting sunlight. So, these are the
Tro
coldest areas. In other words, the coldest areas on the earth pic of C apri corn
MODERATE ZONE
are located between the North Pole and the Arctic Circle in
L
V E R Y C O D Z ONE
the Northern Hemisphere and between the South Pole and Antarctic Circle
the Antarctic Circle in the Southern Hemisphere. South Pole
Heat Zones of the Earth
3. Moderate Zone : Some areas receive moderate sunlight.
They are neither too hot nor too cold. These areas are two; one between the Tropic of
Cancer and the Arctic Circle in the Northern Hemisphere; and the other between the
Tropic of Capricorn and the Antarctic Circle in the Southern Hemisphere.

Longitudes

Latitudes are horizontal lines but longitudes are North
Pole
vertical lines. These lines touch the North Pole on one Line of
Longitude
end and the South Pole on the other end. So, they all
are semi-circles. They are also called meridians . All of

them are of the same length. West East
East
tudes
Longitudes
West
Longi
Longitudes
Longitudes
40º
A total of 360 longitudes are drawn and each is 40º 30º 90º
90º
30º
80º
20º
20º 70º 80º
70º
10º
60º
marked in degrees, just like latitudes. The longitude 10º 0º 0º 10º 20º20º 30º30º 40º40º 50º50º 60º
10º
passing through Greenwich , an observatory near
London, was marked as 0°. This longitude is called
the Prime Meridian . This longitude divides the Earth
into two equal halves : Eastern Hemisphere and the Longitudes
Western Hemisphere .
The longitudes are not parallel, so the distance between them is not uniform. They all
converge at the poles, and their distance increases towards the Equator. The maximum
distance between any two longitudes is at the Equator, where it is about 111 km.
The longitudes lying in the Eastern Hemisphere are marked with ‘E’ and those lying in
the Western Hemisphere are marked with ‘W’. For example, a longitude of 65° in the
8 Contemporary Social Science-5