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Latitude and Longitude

What Is Latitude?

When looking at a map, latitude lines run horizontally. Latitude lines are also known as parallels since they are parallel and are an equal distant from each other. Each degree of latitude is approximately 111 kilometers apart; there is a variation due to the fact that the earth is not a perfect sphere but an oblate ellipsoid or slightly egg-shaped.

Degrees latitude are numbered from 0 degrees to 90 degrees north and south. Zero degrees is the equator, the imaginary line which divides our planet into the northern and southern hemispheres. 90 degrees north is the North Pole and 90 degrees south is the South Pole.

What Is Longitude?

The vertical longitude lines are also known as meridians. They converge at the poles and are widest at the equator (about 111 kilometers apart). Zero degrees longitude is located at Greenwich, England (0 degrees). The degrees continue 180 degrees east and 180 degrees west where they meet and form the International Date Line in the Pacific Ocean. Greenwich, the site of the British Royal Greenwich Observatory, was established as the site of the prime meridian by an international conference in 1884.

How Latitude and Longitude Work Together

To precisely locate points on the earth's surface, degrees longitude and latitude have been divided into minutes (') and seconds ("). There are 60 minutes in each degree. Each minute is divided into 60 seconds. Seconds can be further divided into tenths, hundredths, or even thousandths. For example, the U.S. Capitol is located at 38 degrees, 53 minutes, and 23 seconds north of the equator, and 77 degrees, no minutes and 27 seconds west of the meridian passing through Greenwich, England.