Which meridian runs through greenwich england

International Meridian Conference Meridian Day Telescopes used with Meridian Marks. Where east meets west The Greenwich Meridian separates east from west in the same way that the Equator separates north from south. Over time, some markings will disappear, while others will be restored or renewed. Sunrise and Sunset project. History of one Meridian line For many years, different countries measured longitude from different meridians. How long is the Prime Meridian?

From Pole to Pole, the Prime Meridian covers a distance of 20, km. However, there is an international agreement that the meridian that runs through Greenwich, England, is considered the official prime meridian. Governments did not always agree that the Greenwich meridian was the prime meridian, making navigation over long distances very difficult. Different countries published maps and charts with longitude based on the meridian passing through their capital city.

France would publish maps with 0 longitude running through Paris. Cartographer s in China would publish maps with 0 longitude running through Beijing. Even different parts of the same country published materials based on local meridians. Finally, at an international convention called by U. President Chester Arthur in , representatives from 25 countries agreed to pick a single, standard meridian.

A meridian is a north-south line, selected as the zero reference line for astronomical observations. By comparing thousands of observations taken from the same meridian it's possible to build up an accurate map of the sky. There were two main reasons for the choice. The first was the fact that the USA had already chosen Greenwich as the basis for its own national time zone system.

Therefore the Prime Meridian at Greenwich became the centre of world time. Every place on Earth was measured in terms of its distance east or west from this line. The line itself divided the eastern and western hemispheres of the Earth - just as the Equator divides the northern and southern hemispheres. If you stand with one foot on one side and the other on the left, you are perfectly in the middle of east and west, according to the prime meridian line.

Before this, almost every town in the world kept its own local time. There were no national or international conventions which set how time should be measured, or when the day would begin and end, or what length an hour might be. When the railway and communications networks expanded in the s and s, there needed to be an international time standard.