What is the significance of the Prime Meridian in geography?

The significance of the Prime Meridian in geography lies in its role as the primary reference line for measuring longitude. It is established at 0 degrees longitude and serves as the starting point from which all other longitudes are calculated, extending east and west up to 180 degrees. This division creates the Eastern and Western Hemispheres, providing a framework for map-making and navigation.

Understanding the Prime Meridian is essential for global positioning, as it helps to coordinate time zones and improve communication and travel across different regions of the world. Its establishment at Greenwich, England, has historical importance, as it was chosen during the International Meridian Conference in 1884 to serve as the standard for international timekeeping and navigation.

The other options do not accurately describe the function of the Prime Meridian. For example, measuring altitude pertains to elevation above sea level and is instead connected with other geographic references, such as sea level. The Prime Meridian does not indicate the equator's location, as the equator is a separate line at 0 degrees latitude that divides the Earth into Northern and Southern Hemispheres. Lastly, while it plays a crucial role in global geography, it does not indicate the center of the Earth's landmasses.