Regents Prep: Earth Science: Mapping: Introduction
Latitude and Longitude
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 indicated is:
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.