prime meridian

Thân thiện

The prime meridian is marked by a brass line on the floor of the Royal Observatory.

Definition

1. Proper Noun:
   • The zero-degree line of longitude: The "prime meridian" is the imaginary north-south line on the Earth's surface, defined as having a longitude of 0 degrees. It serves as the universal reference point from which all other longitudes (east and west) are measured. By international convention, it passes through the Royal Observatory in Greenwich, London, England.

Usage

• The "prime meridian" is used as a singular, proper noun, often capitalized. It is the fundamental reference line for the global coordinate system of latitude and longitude.
• It is used to calculate time zones, as Greenwich Mean Time (GMT) and Coordinated Universal Time (UTC) are based on the prime meridian.
• It divides the Earth into the Eastern and Western Hemispheres.

Examples

• Proper Noun:
  • All maps and navigation systems use the prime meridian as the starting point for measuring longitude.
  • The conference established the Greenwich Prime Meridian as the international standard in 1884.
  • When you cross the prime meridian, your longitude reading changes from east to west or vice versa.

Advanced Usage

• "The Greenwich Meridian": This is a direct synonym for the prime meridian, specifically naming its location. Example:
• "The zero meridian": A more technical term emphasizing its longitudinal value. Example:

Variants and Related Words

• Meridian (n): Any imaginary great circle on the Earth's surface passing through the North and South Poles. The prime meridian is the principal meridian.
• Longitude (n): The angular distance east or west of the prime meridian.
• Antimeridian (n): The meridian of 180° longitude, directly opposite the prime meridian, which largely serves as the International Date Line.

Synonyms

• Greenwich Meridian: The specific name for the prime meridian.
• Zero Meridian: Emphasizes its longitudinal coordinate.
• Initial Meridian: A less common term highlighting its role as the starting reference.

Related Phrases

• "East of the prime meridian": Describes locations with positive east longitude values.
  • Tokyo is located far east of the prime meridian.
• "West of the prime meridian": Describes locations with positive west longitude values.
  • New York is located west of the prime meridian.

Học thuật

Noun

1. meridian at zero degree longitude from which east and west are reckoned (usually the Greenwich longitude in England)