Topic - 3 : Latitudes and Longitudes

Latitudes and Longitudes

Equator :-

Equator is a Imaginary line running on the globe that partitions it into halves.

The northern portion of the earth is known as the Northern Hemisphere and Southern half is known as the Southern Hemisphere.

Latitudes and Longitudes are imaginary lines used for locating a place, time and direction on earth.

Furthermore, the location of a place, direction on the earth is also determined by their latitudes and longitudes.

For example if we say a location of a place in terms of latitudes and longitudes it will be like the  location of New Delhi is 28° N, 77° E.

As the shape of the earth is Geoid i.e., it is flattened at the poles (north pole and south pole).

Latitude :

It is the angular distance of a point on the earth’s surface.

It is measured with 180 imaginary lines that form circles around the Earth east - west, parallel to the Equator.

The straight distance of a degree of latitude at the poles is somewhat more than that at the equator because the shape of the earth is slightly flattened at the poles ( Geoid shape ).

For instance at the 0° equator it is 68.704 miles, at 45° it is 69.054 miles and at the poles /shafts it is 69.407 miles. The normal is taken as 69 miles [ 111km ].

Therefore, 1 mile = 1.607 km.

Parallels of Latitude :

Parallels of latitude are equal / parallel circles from the equator to the poles (north and south poles).

As the equator addresses the zero degrees scope. Its distance from the equator to both of the poles is one-fourth of a circle round the earth, it will quantify ¼th of 360 degrees, for example 90°. Hence,   90° north latitude denotes the North Pole and 90 degrees south latitude denotes the South Pole

These Latitudes are measured in "Degrees".

Important parallels of latitudes :

Tropic of Cancer (23½° N) in the Northern Hemisphere.

Tropic of Capricorn (23½° S) in the Southern Hemisphere.

Arctic Circle at 66½° north of the equator.

Antarctic Circle at 66½° south of the equator.

Heat Zones of the Earth :

In the middle of the Tropic of Cancer and the Tropic of Capricorn, the mid –day sun appears to be exactly overhead this happens at least once a year on all latitudes. Therefore, the region during this time gets the greatest heat and is known as the Torrid zone.

The noon time sun never sparkles overhead on any latitude past the Tropic of Cancer and the Tropic of Capricorn. The point of the sun's beams continues diminishing towards the poles. All things considered, the regions limited by the Tropic of Cancer and the Arctic circle in the northern half of the globe, and the Tropic of Capricorn and the Antarctic circle in the southern side of the equator, have moderate temperatures. These are, subsequently, called Temperate zones.

Regions lying between the Arctic circle and the north pole in the northern side of the equator and the Antarctic circle and the south pole in the southern half of the globe, are freezing. It is on the grounds that here the sun doesn't raise much over the skyline. In this way, its beams are continually inclining. These are, hence, called Frigid zones.

Longitude :

The meridian which passes through the Greenwich, where the British Royal Observatory is found. This meridian is considered as the Prime Meridian.

It is 0° longitude and from it, we consider 180° towards the east and 180° towards the west. The Prime Meridian and 180° meridian separates the earth into two equal parts i.e., the Eastern Hemisphere and the Western Hemisphere.

Distances between them are estimated in degrees of longitude, every degree is additionally isolated into minutes, and minutes into seconds.

A Circle = 360 Degrees

1 Degree = an hour

1 Minute = 60 Seconds

Longitude and Time : 

Since the earth makes one complete revolution in one day or 24 hours, it will pass through 15° in one hour or 1° in four minutes.

As we know that the Earth rotates from west to east, so every 15° we go eastwards, neighborhood / local time is progressed by 60 minutes. And in the event that we go westwards, local time is hindered by 60 minutes.

We may in this way infer that places east of Greenwich see the sun prior and acquire time, while west of Greenwich see the sun later and lose time.

In the event that we know G.M.T., to figure out nearby time, we just need to add or deduct the distinction in the quantity of hours from the given longitude.