The system of geographic coordinates measures the location of any point on the earth’s surface. The coordinates consist of the latitude and longitude of any point.
Photo: geographic coordinates (Creative Commons: A Learning Family).
Click on the map to view the full sized image.
Lines of Latitude
In the map provided, lines of latitude are the horizontal lines. They run from the left to the right on the map. The equator is the reference or zero latitude. All other lines of latitude are measured in degrees north or south of the equator.
Poles: the North Pole is the latitude that is 90 degrees north (90°N) of the equator. The South Pole is 90 degrees south (90°S) of the equator. These are located at the top and bottom of the displayed map.
Tropics: the Tropic of Cancer is latitude 23.5 degrees north (23.5°N) of the equator. The Tropic of Capricorn is latitude 23.5 degrees south (23.5°S) of the equator. The significance of these two lines of latitude is that they represent the range of locations where the noon sun can be directly overhead on a given day of the year.
Circles: the Arctic Circle is latitude 66.5°N of the equator. The Antarctic Circle is latitude 66.5°S of the equator. The locations between these circles and the North or South Poles are places where there is no daylight on a given day of the year.
In the map provided, lines of longitude are the vertical lines. They run from the top to the bottom of the map. The Prime Meridian is the reference or zero longitude. All other lines of longitude are measured in degrees west or east of the Prime Meridian.
Every location on the earth’s surface can be described by its geographic coordinates (latitude and longitude). Davao City, Philippines for example has the coordinates of 7°N, 125°E. In other words, Davao City is located 7 degrees north of the equator and 125 degrees east of the Prime Meridian.
Improving Your Reading and Thinking Skills
Think for a few moments. Try to recall the major ideas in this article. When you are done, click the box below for a list of main ideas.
How did you do? With practice, you should be able to identify many of the major ideas. You may even discover some important ideas that aren’t listed.