Longitude is measured in reference to which line?

Longitude is measured in reference to the Prime Meridian, which is defined as 0 degrees longitude. It serves as the starting point for measuring degrees east and west around the globe. The Prime Meridian runs through Greenwich, England, and establishes the standard for global navigation and mapping.

In geographical terms, longitude indicates how far east or west a location is from this line. Each degree of longitude corresponds to a specific angle relative to the Earth’s center, helping to create a grid system for identifying locations on the globe.

In contrast, the Equator, which is used to measure latitude, represents 0 degrees latitude and divides the Earth into the Northern and Southern Hemispheres. The Tropic of Cancer and the International Date Line serve different purposes, with the Tropic marking a significant latitude for solar phenomena, while the International Date Line primarily helps manage time zones across the globe. Understanding this distinction crystallizes the role of the Prime Meridian in the measurement of longitude.