Geography Reference
In-Depth Information
Figure 4-4:
Fam-
ilies of map pro-
jections.
Azimuthal (or planar):
A flat piece of paper (or plane, hence
planar
) is placed against the
globe. The globe is then projected onto the flat paper, rendering a flat map.
Cylindrical:
Apapercylinderisplacedoveraglobe.Theglobeisprojectedontothepaper.
The cylinder is then cut vertically and unwrapped from the globe, yielding a flat map of the
world.
Conical:
A conical paper
hat
is placed on the globe. The portion of the globe under the
hat is projected onto the paper. The paper is cut in a straight line from its edge to the tip of the
cone. The cone is then opened up and put down flat.
Thisremindsmetoremindyouthattheprocessofprojectiondoesnotliterally involveproject-
ing a globe onto a flat surface. Instead, mathematical formulas are used to plot the locations of
lines (latitude, longitude, continental boundaries, and so on) on maps. Thanks to satellite im-
agery and high-altitude photography, you can now check the accuracy of your work in a way
that was never possible before.
Five noteworthy liars
Here are five rather well known projections that represent the range of formats shown in Fig-
ure 4-4. There will not be a test over this. I repeat, there will not be a test. So don't try to
memorize this stuff, but instead, just sort of let the maps visually soak in to give you an appre-
ciation of the variety of projections that are available.
