Preparation: Locating Yourself on a Globe

  
Approximately 70% of the Earth’s surface is covered by water, so navigating from point A to point B requires a method that does not rely on landmarks. The most accurate means of location on a globe is a grid of imaginary lines that intersect at large angles. Any feature on the globe can be located by specifying the two intersecting lines that pass through it. Such a system of location, longitude and latitude (Fig. 1), has been in use successfully for thousands of years and dates back to the Greeks and Egyptians. The great Greek astronomer Hipparchus described longitude and latitude in the second century B.C.
 



Fig. 1: Longitude and Latitude

 
  • Longitude measures east-west position on a globe.  More...
  • Latitude fixes position north-southMore...
  • Great circles are arcs of circles that connect two points and represent the short distance between the two points.  More...
 
To prepare for the Activities, select one of the following files:
  

  

Copyright Houghton Mifflin Company. All Rights Reserved.
Terms and Conditions of Use, Privacy Statement, and Trademark Information