Lines of Latitude

The lines of latitude form one of the coordinates of the grid system. A line of latitude represents the angular distance of a place located to the north or south of the Equator. The Equator is at 0° latitude. Lines of latitude are the imaginary lines joining all places having the same latitude towards north or south of the Equator. These are also called parallels of latitudes as they run parallel to the Equator. There are 181 parallels of latitudes.

Main Latitudes

The Equator is the longest latitude.
The North Pole is located at 90°N.
The South Pole is located at 90°S.
The Tropic of Cancer is located at 23 ½° N in the Northern Hemisphere.
The Tropic of Capricorn is located at 23 ½° S in the Southern Hemisphere.
The Arctic Circle is located at 66 ½° N of the Equator.
The Antarctic Circle is located at 66 ½° S of the Equator.

Each latitude forms a full circle. The Equator is a great circle. The length of the circles decreases as we move towards the poles.

Northern and Southern Hemispheres

The Equator divides the Earth into two equal parts. The part lying to the north of the Equator is known as the Northern Hemisphere and the part lying to the south of the Equator is known as the Southern Hemisphere.
The North Pole (90°N) is located in the Northern Hemisphere at the extreme end of the Earth. The South Pole (90°S) is located to the south of the Equator in the Southern Hemisphere.
The length of the Equator is equal to the circumference of the Earth which is 40,077 km. Because the Equator is a great circle and the circumference of a circle is equal to 360°, 1° angular distance is approximately equal to 111 km.
Latitudes help us to find the distance of any place from the Equator based on its degree of latitude. Example: Chennai is located at 13°N. Because 1° latitude = 111 km, the distance of Chennai from the Equator will be 13 × 111 = 1443 km.

Major Heat Zones of the Earth

Latitudes divide the Earth into three different heat zones. Because the Earth is spherical, different parts of the Earth get heated differently. Based on the heat received from the Sun, the Earth is divided into three heat zones. They are

Torrid Zone:
It is a region between the Tropic of Cancer and the Tropic of Capricorn. This region receives the direct vertical rays of the Sun for almost the whole year. Therefore, this zone gets maximum heat from the Sun. This zone is known as the torrid or tropical zone.

Temperate Zone:
This zone lies between the Tropic of Cancer and the Arctic Circle in the Northern Hemisphere and between the Tropic of Capricorn and the Antarctic Circle in the Southern Hemisphere. This zone gets the slanting rays of the Sun as the angle of the Sun’s rays goes on decreasing towards the poles. Thus, this zone experiences moderate temperature.

Frigid Zone:
The Frigid Zone lies between the Arctic Circle and the North Pole and between the Antarctic Circle and the South Pole. This zone is also known as the polar region. Because it receives the extreme slanting rays of the Sun, the temperature is extremely low throughout the year. This is the reason the polar regions are generally covered with ice.

Also, Read The Earth’s Grid