Numbering and Measurement of Meridians

1. Numbering of Meridians

– Meridians are numbered from 0 degrees at the Prime Meridian, which passes through Greenwich, England.

– The numbering of meridians goes from 0 degrees at the Prime Meridian to 180 degrees east (E) and 180 degrees west (W).

2. Measuring Longitude

– Longitude is used to measure the east-west position of a location on the Earth’s surface.

– Longitude is measured in degrees east or west of the Prime Meridian, which is defined as 0 degrees longitude.

3. Degrees East and West

– Locations east of the Prime Meridian are measured in degrees East (E), from 0 degrees to 180 degrees East.

– Locations west of the Prime Meridian are measured in degrees West (W), from 0 degrees to 180 degrees West.

4. The 360-Degree System

– The complete system of meridians and longitude measurement covers a 360-degree circle around the Earth.

– This is achieved by combining the 180 degrees East and 180 degrees West, creating a continuous range from 0 to 360 degrees.

5. The International Date Line

– The International Date Line is an imaginary meridian located approximately 180 degrees east or west of the Prime Meridian.

– It marks the place where the date changes by one day, moving from one side of the line to the other.

6. Relationship to Time Zones

– Meridians are also used to define time zones, with each time zone covering a 15-degree span of longitude.

– This allows for the standardization of time across different regions and the coordination of global activities.

Meridians, the imaginary north-south lines on the Earth’s surface, play a crucial role in the geographic coordinate system. They provide the framework for measuring longitude and enable the establishment of standardized time zones across the globe.