Understanding Maps-

Cartography

The Olde World

Maps vs. Globes• 2 dimensional• Flat• Distorted• Shows small

details• Handy/can fold

• 3 dimensional• Spherical• More accurate• Shows large

details• inconvenient

Map vs. Globe

Which is bigger … Greenland, Mexico or Australia

Map Projections

•Mercator•Gnomonic/Azimuthal•Conic

MERCATOR PROJECTION• Made as if you

wrapped a cylinder around a globe

• Parallels and Meridians appear as straight lines

• Accurate at equator• Distorted at poles

Gnomonic/Azimuthal Projection• Made as if paper

touched one point on globe

• Useful for air travel/navigation

• Accurate at point of contact

• Uneven spacing between parallels

Conic Projection• Made by placing

paper cone over globe

• Cone touches along one parallel

• Accurate at that point• Used for mid latitude

navigation• Many sections-

polyconic

GREAT CIRCLE• Any circle that divides

the globe into 2 equal halves

• Useful in navigation• Shows the shortest

distance between 2 points

Reading a Map• LEGEND—symbols used to interpret a map (see p 60)

• MAP SCALE- indicates the relationship between distance on a map and distance on Earth

A) GRAPHIC B) FRACTIONAL C) VERBAL

GRAPHIC SCALE• Shows a printed line

divided into parts and labeled

• You can measure distance with a ruler and compare to line

Fractional Scale• States the map scale as a ratio• Ex.: 1:24 000 means one unit on the map equals 24000 units on the Earth

Verbal Scale• Makes a written statement in words expressing the scale• Ex.: “One centimeter equals one Kilometer”

Ex. : “One inch equals 5.2 miles.”

                                                  

They all mean the same thing.

http://www.dot.state.oh.us/map1/ohiomap/images/county/legend.jpg

Topographic Map Scales

http://academic.brooklyn.cuny.edu/geology/leveson/core/wayne_web/distance%20and%20direction/scale-direction-ex2.htm