Meridian Longitude ((install)) Today

The Grid of the World: The Significance of Meridians and Longitude

What Is a Meridian of Longitude?

A meridian is an imaginary half-circle from the North Pole to the South Pole. Unlike latitude (which has a natural zero at the equator), longitude’s zero line is arbitrary—chosen by people, not nature.

Key Takeaways

• Meridian longitude lines run pole-to-pole, measuring east-west position.
• The Prime Meridian at Greenwich (0°) is the international standard.
• Longitude is fundamentally linked to time (15° per hour).
• One degree of longitude varies in distance from 111 km (equator) to 0 km (poles).
• Modern GPS relies on precise longitude calculations using atomic time.

• National Oceanic and Atmospheric Administration (NOAA) - Understanding Longitude and Latitude
• International Meridian Conference - History of Longitude
• Britannica - Longitude and Latitude

• Use “longitude” to refer to the east‑west coordinate value (e.g., “The longitude of Paris is 2°21′ E”).
• Use “meridian” to refer to the great semicircle (e.g., “The Greenwich meridian”).
• The phrase “meridian longitude” is redundant but occasionally appears in informal or pedagogical writing to emphasize the connection. It is not standard in technical literature.

What is a meridian write three features of meridian - Brainly.in

Furthermore, meridian lines are used in astronomy. Telescopes are mounted on "meridian circles" to track celestial objects precisely as they cross the local meridian of the observatory. This is called a "transit," and it is how star catalogs are measured.