Antimeridian And Prime - Meridian

Here’s what they are, why they matter, and where things get weird. What it is: The starting point for measuring longitude. It runs through Greenwich, London , UK, and divides Earth into Eastern Hemisphere (0° to 180° east) and Western Hemisphere (0° to 180° west).

(e.g., plotting earthquakes or shipping routes), if you center a map on the Atlantic, the Pacific gets split — but if you center on the Pacific, the Atlantic gets split. No perfect flat map avoids the antimeridian problem. antimeridian and prime meridian

Today, the true zero-longitude line is actually about 100 meters east of the original Greenwich telescope, due to modern GPS using the International Reference Meridian (IRM), which aligns with satellite measurements. But the historic line still draws tourists. 2. The Antimeridian (180° longitude) What it is: Exactly halfway around the world from the Prime Meridian: 180° east / 180° west — they’re the same line. Here’s what they are, why they matter, and