In 1884, the International Meridian Conference met in Washington, D.C., and established the (passing through the Royal Observatory in Greenwich, London) as the world's official Prime Meridian. It is designated as 0° longitude . How Longitude is Measured Longitude is measured in degrees, minutes, and seconds:
Let’s clear up a few lingering myths:
A is an imaginary semicircular line on Earth’s surface connecting the North Pole to the South Pole. Every meridian is a line of constant longitude . Thus: meridian longitude
In strictly geographic terms, a is a semi-great circle connecting the North Pole to the South Pole. Every line of longitude is exactly one-half of a great circle—meaning it represents the shortest path between two points on the Earth’s surface, but only if you travel along that specific line. In 1884, the International Meridian Conference met in