Geography Reference
In-Depth Information
then a north arrow placed on one part of the map may point in a different direction than a north arrow
placed elsewhere.
Actually, it's possible to make a map that keeps true directions throughout its surface. The Mercator
Projection, a rather famous map introduced later in the chapter, is an example. But maintaining true
direction can only be achieved by distorting something else. As the Mercator Projection shows, that
something else is distance and area.
Shape
Shape refers to the outline of objects on Earth's surface. In the process of projection, you can transfer
a continent or island from a globe to a flat surface while keeping its shape pretty shape intact. Then
again, you can make a complete mess of things because stretching here and pulling there is part and
parcel to the projection process and may play havoc with shape.
For example, compare Greenland in Figures 4-2 and 4-3. Notice that the island appears very differ-
ently in the two maps. Greenland's shape is virtually correct in Figure 4-3 because the lines of lon-
gitude meet at the North Pole, just as in reality. In Figure 4-2, however, Greenland is seriously mis-
shapen because the lines of longitude do not meet at the North Pole but are instead spread apart in the
polar area. The result is a greatly distorted Greenland.
But before we sing the praises of Figure 4-3, compare the shape of Northern Africa on both maps.
Africa appears much more accurately in Figure 4-2 because in that map, the spacing of North Africa's
lines of latitude and longitude are pretty much true to life. In Figure 4-3, however, North Africa ap-
pears to have become an accordion. It has been stretched laterally out of proportion to its true shape.
That happens because as the lines of longitude extend outward from the center point — the North
Pole — the projection excessively stretches the distance between them. As a result, North Africa has
a flattened appearance.
Area
Area refers to the size of objects on Earth's surface. As is the case with shape, you can transfer
(project) some features from a globe onto a flat surface while keeping sizes accurate relative
to other objects on Earth's surface. Then again, you can make a complete mess of things. As
to the reasons why, well, I apologize that this is sounding like a stuck record, but the simple
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