Longitude is a geographic coordinate that specifies the east-west position of a point on the Earth's surface. It is measured in degrees, with the Prime Meridian (which passes through the Royal Observatory in Greenwich, England) at 0° longitude and the International Date Line at 180° longitude. Longitude is used in conjunction with latitude to define the location of a place on the Earth's surface.
Here are a few examples of longitude:
- 0° longitude: The Prime Meridian is an imaginary line that runs from the North Pole to the South Pole and is located at 0° longitude. It is the line of demarcation between the Eastern and Western Hemispheres.
- 60° east longitude: This is a location that is located 60° east of the Prime Meridian. Some cities that are located around 60° east longitude include Moscow, Russia (37.62° E) and Tehran, Iran (51.42° E).
- 120° west longitude: This is a location that is located 120° west of the Prime Meridian. Some cities that are located around 120° west longitude include Los Angeles, California (118.24° W) and Santiago, Chile (70.66° W).
- 180° longitude: The International Date Line is an imaginary line that runs from the North Pole to the South Pole and is located at 180° longitude. It is the line at which the date changes as you travel east or west.
Longitude is usually expressed in degrees, minutes, and seconds, with each degree being divided into 60 minutes and each minute being divided into 60 seconds. For example, the longitude of New York City is 74.0060° W, which is equivalent to 74° 0' 21.6" W.