In order to locate positions on the Earth's
surface, a coordinate system is used. This is basically just a
grid, with horizontal and vertical lines. By indicating a
horizontal and vertical coordinates, an exact position can be
located on the grid.
|For example, in the grid on the right, the point
10 on the horizontal (X) axis;
and 50 on the vertical (Y) axis.
A grid like this can be used to locate positions on
the Earth's surface as well. This is slightly
complicated by the fact that the Earth has a spherical,
not flat, surface.
Maps can be created that will indicate many
characteristics of a location's surface. One of the most
common characteristics that is indicated is elevation.
Topographic (Contour) Maps, indicate the
elevation of all the locations on a given map. In the
Topographic Map section you will learn how to draw, use,
and interpret these maps.