<P> In 1884, the United States hosted the International Meridian Conference, attended by representatives from twenty - five nations . Twenty - two of them agreed to adopt the longitude of the Royal Observatory in Greenwich, England as the zero - reference line . The Dominican Republic voted against the motion, while France and Brazil abstained . France adopted Greenwich Mean Time in place of local determinations by the Paris Observatory in 1911 . </P> <P> The "latitude" (abbreviation: Lat., φ, or phi) of a point on Earth's surface is the angle between the equatorial plane and the straight line that passes through that point and through (or close to) the center of the Earth . Lines joining points of the same latitude trace circles on the surface of Earth called parallels, as they are parallel to the equator and to each other . The north pole is 90 ° N; the south pole is 90 ° S . The 0 ° parallel of latitude is designated the equator, the fundamental plane of all geographic coordinate systems . The equator divides the globe into Northern and Southern Hemispheres . </P> <P> The "longitude" (abbreviation: Long., λ, or lambda) of a point on Earth's surface is the angle east or west of a reference meridian to another meridian that passes through that point . All meridians are halves of great ellipses (often called great circles), which converge at the north and south poles . The meridian of the British Royal Observatory in Greenwich, in south - east London, England, is the international prime meridian, although some organizations--such as the French Institut Géographique National--continue to use other meridians for internal purposes . The prime meridian determines the proper Eastern and Western Hemispheres, although maps often divide these hemispheres further west in order to keep the Old World on a single side . The antipodal meridian of Greenwich is both 180 ° W and 180 ° E . This is not to be conflated with the International Date Line, which diverges from it in several places for political reasons, including between far eastern Russia and the far western Aleutian Islands . </P> <P> The combination of these two components specifies the position of any location on the surface of Earth, without consideration of altitude or depth . The grid formed by lines of latitude and longitude is known as a "graticule". The origin / zero point of this system is located in the Gulf of Guinea about 625 km (390 mi) south of Tema, Ghana . </P>

The standard north-south coordinate on a globe or a map is