The Importance Of Longitudes In Determining A region’s Time Zone

The vertically drawn imaginary lines called longitudes measure time as there are 360 meridians of the longitudes that divide the Earth into 360 parts and with reference to the centre point called the Greenwich Mean Time, the time zones are determined. Although these latitudes and longitudes altogether form the grid( the diagram of longitudes and latitudes) serving many significance.

What are latitudes?

Latitude is one of the most basic terms used in geography. The latitudes are the horizontally drawn imaginary lines or the geographical coordinates which divide the earth into the south and north region. The range of the latitudes varies from 0 degrees on the equator to 90 degrees towards north and south at the poles. 

These imaginary lines tend to be parallel to the equator, running from east to west or west to east, and go on decreasing in radius towards the poles. 

Latitudes towards the north and south are named differently and serve different information about the regions. The significance of some of the important parallel imaginary lines called latitudes are as follows:

• Equator: the centerline running from east to west that divides the earth into two halves. The equator lies at 0 degrees on the earth’s surface.
• Cancer: the latitude just above the equator towards the north pole is called the tropic of cancer. This exists at 23.43 degrees north.
• Capricorn: moving towards the south of the equator, tropic of Capricorn exists at 23.43 degrees.
• Arctic circle: above the tropic of cancer lies the arctic circle, positioned at 66.57 degrees north.
• Antarctic circle: below the tropic of Capricorn is the antarctic circle. This is situated close to the south pole at an angle of 66.57 degrees south.

What are longitudes?

Longitudes are the imaginary lines drawn vertically on the earth’s surface. The longitudes are other geographic coordinates used to specify the east and west on the earth’s surface. The longitudes are measured by term degrees. 

The significance of the longitudes is that these are used to measure the time zones for the various regions on the earth. Here, the meridians running from north to south go on connecting points along the same longitude. The meridian which exists at 0 degrees on earth is called the prime meridian and is taken as the reference line for all other meridians. 

This prime meridian is situated just near the royal observatory in Greenwich in England. Moreover, this prime meridian is at 0 degrees longitude. 

There also exists the sign convention for the longitudes. For instance, the longitudes towards the east are taken as positive while the ones towards the west are taken as negative.

Eventually, each longitude differs by 15 degrees and the longitudes extend toward east and west up to 180 degrees and -180 degrees respectively.

How do latitudes and longitudes help to determine time?

Time determination for the various regions is a case done with the help of longitudes and not latitudes. This has a reason behind which is the Earth’s rotation.

The earth rotates vertically and hence the longitudes are used which are also the vertically drawn imaginary lines. Each longitude makes a difference by 15 degrees leading to a 1-hour difference as we cross 1 longitude with respect to the positioning of the sun. 

This calculation of 15 degrees leading to 1 hour is derived from the logic that one rotation of the earth completes in 24 hours and it covers a total of 360 degrees of longitudes. Therefore, this simply means that the earth tends to cover 15 degrees of the longitude each hour where degrees are subdivided into minutes and seconds.

Moreover, the determination of longitudes is also possible using the local times. The longitudes also give information about the geodetic normal or so-called gravity direction.

Conclusion

Therefore, the latitudes and longitudes are those imaginary lines drawn on the earth’s surface that altogether form a grid-like structure. Further, this grid-like structure is the diagram of latitude and longitude that helps us to determine the various regions on the earth and most importantly the time zones for every region. Additionally, among all the latitudes the equator is the most important imaginary line. Whereas talking about the longitudes, these are the imaginary lines or circles which intersect all the three north poles, the south pole, and the equator.