Latitude and longitude Lines of latitude and longitude are used to locate places accurately on the Earth's surface. Latitude Lines of latitude circle the Earth in an east-west direction. They are parallel. They are different lengths, eg: the equator is 40,075 km long the Antarctic circle is 17,662 km long the South Pole is 0 km long Important lines of latitude: the equator (0°) the Tropic of Cancer (23.5° north) the Tropic of Capricorn (23.5° south) the Arctic circle (66.5° north) the Antarctic circle (66.5° south) the North Pole (90° north) the South Pole (90° south) Longitude Lines of longitude run from the top of the Earth to the bottom. They are not parallel as lines of latitude are - they meet at a point at the north and south poles and are called meridians. They divide the Earth into segments, like an orange. Some important details about these lines include: The line which runs through Greenwich in London is called the Greenwich Meridian or Prime Meridian. The Prime Meridian is 0° longitude. The Earth is then divided into 180° east and 180° west. The International Date Line lies at 180° east/west. The index of an atlas gives shows where places can be found, eg Birmingham, UK - 52° north 1° west. This means that Birmingham is located at approximately latitude 52 north and longitude 1 west.