MERIDIANS AND PARALLELS A series of imaginary vertical and horizontal lines enables us to identify the exact location of places on Earth.
Meridians are semicircles which go from one pole to the other. The prime meridian, or Greenwich meridian (0º), is the point of reference for other meridians.
Parallels are circles which are perpendicular to the meridians. The equator is the most important parallel and is the point of reference for the other parallels.
Other important parallels, from north to south, are: The Arctic Circle
Latitude and longitude indicate geographical coordinates: the exact location of a place on the Earth.
Latitude is measured by using the parallels which start at the equator (0º). At the poles they are 90º They are lalitude north (N) or south (S).
They run vertically from 0º to 180º to the west (W)… Longitude is measured by using the meridians which start at the prime meridian (0º). …and 0º to 180º to the east (E).