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Chapter 2                                                                                                  Lesson 3

Putting Maps to Work

I. Maps for Different Purposes

A.   Different types of maps show different kinds of information.

a.      Thematic Map:  a map that gives information on a particular topic.

B.    Cartographers must decide what information to include and how to show it.

II. The Shape of the Earth

A.     A map is a means of giving information about the earth.

B.     Cartographers try to make accurate maps, but they are faced with one serious problem: the shape of the earth.

a.      The earth is a sphere, and a map is flat.  It is impossible for cartographers to accurately show the earth’s curved surface on the flat surface of a map.

C.     Cartographers developed different types of map projections, or ways to show the earth's curved surface.

a.      Projection: a system for representing the three-dimensional world on a two-dimensional surface.

D.     There are four different projections.

a.      Mercator:  the shapes of the continent are fairly accurate, but their sizes are greatly distorted, especially near the poles.

b.     Peters:  the sizes of the continents are accurate as compared with each other, but the shapes of the continents are distorted.

c.     Goode’s: combination of two other projections.  The map shows little distortion of size or shape. 

d.      Robinson:  the sizes and shapes of continents and the distances between places are fairly accurate.  This is a good compromise.