Globe – Latitudes & Longitudes: Equator, Prime Median, Importance

The compilation of these Globe-Latitudes and Longitudes Notes makes students exam preparation simpler and organised.

Latitudes and Longitudes

Did you know, that there is a way for you to see the entire world at a glance? Surprised? Yes, with the help of a globe, one can see the entire earth at a glance. Not just the different continents and oceans, you can even see the different lines like latitudes and longitudes on the globe. But, what is this globe, and what are the latitudes and longitudes? Let’s find out more about Globe – Latitudes and Longitudes.

Introduction to Globe

A globe is a true model of the earth, in a very compact form. In a globe, there is a needle called the axis that is fixed through the globe in a tilted manner. This axis of the globe passes through two extreme points: known as the Poles (the North Pole and the South Pole). The axis is shown in the form of a needle on the globe. In reality, the earth has no such axis.

Globe - Latitudes and Longitudes

Equator
The Equator is the circle passing through the center of the earth. It is perpendicular to the axis and goes on to divide the earth into two Hemispheres, the Northern and the Southern.

There are a number of more circles parallel to the equator. These circles have their centers on the axis and have different radii. Such circles are known as the Parallels of Latitudes. You can identify these parallels using the degrees. On the equator, the latitude is zero degrees.

Prime Median
There is a circle which passes through Greenwich in Britain. It is perpendicular to the equator, and parallel to the axis. It is known as the Prime Meridian. Prime Meridian divides the earth into two Hemispheres, the Eastern and the Western.

Together, the Equator and the Prime Meridian divide the earth into four equal parts. There are a number of more circles parallel to the Prime Meridian. These have their center at the center of the earth and have equal radii. Such circles are known as the Degrees of Longitudes.

Latitudes and Longitudes
In the Northern Hemisphere, the latitudes are designated as degrees north (°N). For instance, 10°N, 20°N, and so on till 90°N (which is the North Pole). Similarly, there are latitudes in the Southern Hemisphere. These are designated as degrees south (°S), and 90°S is the South Pole.

The longitudes are identified with the help of degrees. Prime meridian represents the zero degrees longitude. In the Eastern Hemisphere, the longitudes are designated as degrees east (°E), e.g. 10°E, 20°E, and so on till 180°. The same is the case with the Western Hemisphere. Further, the degrees are divided into minutes and minutes into seconds.

Please note: For a minute, the symbol is an apostrophe (‘) and for a second, the symbol is a double apostrophe (“). So, 60′ (60 minutes) make up a degree and 60″ (60 seconds) make up a minute. In the same manner, the 30’ means half a degree and 40” means two-thirds of a minute.

Importance of Latitudes and Longitudes

Two points on earth can lie at the same latitude but still be far away from each other. Also, two distant points may lie on the same longitude. But only one point lies on a particular pair of latitude and longitude. So latitudes and longitudes are helpful in locating a point on earth.

Globe - Latitudes and Longitudes 1

Important Latitudes and Longitudes

The Arctic Circle and the Tropic of Cancer are the special latitudes in the Northern Hemisphere. They are situated at 66 1/2° N and 23 1/2° N respectively. On the other hand, the Antarctic Circle and the Tropic of Capricorn are the special latitudes in the Southern Hemisphere. They are situated at 66 1/2° S and 23 1/2° S respectively.

Heat Zones
The area between the Tropic of Cancer and the Tropic of Capricorn receives the maximum heat from the Sun. This region is known as the Torrid Zone. The area between the Arctic Circle and the Tropic of Cancer in the Northern Hemisphere, and that between the Antarctic Circle and the Tropic of Capricorn in the Southern, have moderate temperatures. These regions are the Temperate Zones.

Lastly, the area north of the Arctic Circle and that south to the Antarctic Circle are close to the Poles and receive sunlight of very low intensity. So it is very cold here. These regions are called the Frigid Zones. The Frigid Zones, the Temperate Zones, and the Torrid Zone are called the Heat Zones.

Example:

Question:
Explain the concept of time zones.
Answer:
The sun does not shine When it is 12 noon at a time, it means that the sun is not at all visible at the place on the other side of the earth. So it must be midnight there. In fact, we can say that the time difference is 24 hours at 360 degrees longitudes apart. So every longitude brings a difference of 4 minutes. This gives us the concept of Time Zones. Two consecutive time zones differ by the hour. The time at a particular place is said to be the local time.