Prime Meridian

Definition

The prime meridian is an imaginary line that runs from the North Pole to the South Pole, passing through Greenwich, England. It is the reference line from which longitude is measured, with locations east and west of the prime meridian designated as having positive or negative longitude values, respectively.

5 Must Know Facts For Your Next Test

1. The prime meridian was officially adopted as the international standard in 1884 at the International Meridian Conference held in Washington, D.C.
2. The prime meridian passes through the Royal Observatory in Greenwich, England, which was established in 1675 and became the center of global time-keeping.
3. Locations west of the prime meridian are assigned negative longitude values, while locations east of the prime meridian are assigned positive longitude values.
4. The prime meridian is the basis for the Universal Time (UT) system, which is the standard time used for astronomical observations and scientific purposes.
5. The position of the prime meridian has been refined over time, with the current definition based on the location of the International Bureau of Weights and Measures in Sèvres, France.

Review Questions

• Explain the significance of the prime meridian in the context of Earth's coordinate system.
  • The prime meridian is the fundamental reference line for the Earth's coordinate system, as it defines the 0-degree longitude line. This line serves as the starting point for measuring the east-west position, or longitude, of any location on the planet. The prime meridian, along with the equator at 0 degrees latitude, form the basis for the global grid system that allows for the precise mapping and navigation of the Earth's surface.
• Describe the historical and scientific importance of the prime meridian's location in Greenwich, England.
  • The prime meridian's location in Greenwich, England was chosen due to the presence of the Royal Observatory, which was established in 1675 and became the center of global time-keeping. The observatory's role in astronomical observations and the development of accurate clocks and navigational techniques led to the prime meridian's adoption as the international standard in 1884. The prime meridian's association with Greenwich has made it a significant cultural and scientific landmark, as it represents the global reference point for measuring time and location.
• Analyze the relationship between the prime meridian, longitude, and the concept of Universal Time (UT).
  • The prime meridian is the basis for the Universal Time (UT) system, which is the standard time used for astronomical observations and scientific purposes. This is because the prime meridian defines the 0-degree longitude line, and locations to the east and west of this line are assigned positive and negative longitude values, respectively. The UT system is synchronized with the Earth's rotation, with the prime meridian serving as the reference point for the global timekeeping system. This integration of the prime meridian, longitude, and UT allows for the precise coordination of scientific and navigational activities across the world.

Related terms

Longitude:

The east-west position of a location on the Earth's surface, measured in degrees east or west from the prime meridian.

Latitude:

The north-south position of a location on the Earth's surface, measured in degrees north or south from the equator.

Equator:

The imaginary line that divides the Earth into the Northern and Southern hemispheres, located at 0 degrees latitude.