Do Maps Lie Maps Lie.pdf · Short answer is YES All maps lie because they DISTORT the scale and...
Transcript of Do Maps Lie Maps Lie.pdf · Short answer is YES All maps lie because they DISTORT the scale and...
Do Maps Lie?A Presentation on Map Projections
Short answer is YESAll maps lie because they DISTORT the scale and shape of objects
DISTORT: to bend, stretch and or change the original shape and relationship to other objects
Distortion happens when you try to translate a 3D object like Earth into 2D object like a flat map
1. Distortion ExampleThis projection greatly distorts the size of the Northern Hemisphere over the Southern, when
in fact, both are equal in size.
2. Distortion ExampleThis projection greatly distorts the size of the former Soviet Union, making it look bigger
than all of Africa. In reality, Africa (30 million km2) is much larger than the Soviet Union (22 million km2).
3. Distortion ExampleThis projection greatly distorts the size of the People’s Republic of China versus the size of Greenland. In fact, China (9.5 million km2) is almost 4 times larger than Greenland (2.1
million km2)!
4. Distortion ExampleIn this projection Norway appear to be the same size as India. In fact, India (3.3 million
km2) is more than three times larger than Norway (1.1 million km2)!
5. Distortion ExampleThis projection shows that Europe is larger than South America. In reality, South America
(17.8 million km2) is almost twice as large as Europe (9.7 million km2)!
Is there such thing as “Purposeful Distortion”?
Yes, Cartograms...
Carto - means ‘paper’ in Latin... other words: Cartoon, Carton
Gram - means ‘written record’ in Greek... other words: grammar, anagram
Geographers use Cartograms to show geographical information and something else... Like a combination graph and map
Bottomline:Because of distortion, all maps lie...
The Earth is a sphere and so are globes. With globes there is NO distortion of either size and or
scale.
...So Why Not Globes?
... Unfortunately, globes are impractical for most everyday uses
Can you list any drawbacks to using globes:
Drawbacks of GlobesToo big to put in your pocket...
Not specific enough, not very detailed
Not great for every day use; not practical
Why is it important to know un-distorted shapes for everyday use
Not CHEAP!!!
Types of Maps
• Political• Used to identify human boundries, like countries, states, counties,
etc.
Types of Maps
• Physical• Used to identify the earth’s features like elevation, oceans, and
• other permanent features.
Types of Maps
• Other• These may include climate, precipitation, population, etc.
Average January Temperature
Map Projections
Not all maps distort in the same way...
Some map projections distort size more than scale or vice versa
All depends on your purpose... different map projections for different purposes
1. Mercator ProjectionThis map projection is good for navigation around the Equator; however greatly distorts size and scale towards the poles (e.g. size of Greenland). This map is most frequently used for sea
travel.
2. Conic ProjectionThis map projection is good for things that are mostly East to West (Like the 48 Continental US States). However, distorts things from North to South (look at South America in the lower
right-hand corner).
3. (Interrupted) SinusoidalThis map projection is good for things that are North to South (like North and South
America). However because this map is interrupted, it greatly distorts scale from East to West (how wide is the Pacific Ocean?)
4. Robinson ProjectionThis map projection is one we will use most frequently... strikes a good balance between
distortion and accurately representing a sphere on flat paper. However, still distorts objects near the poles and scales from East to West vary.
So what would a completely undistorted map of the world look
like?
This doctored satellite image of the Earth is interrupted - show while it accurately shows the shape of all major land forms, it greatly distorts their relationship to one another.
Consider, how far is from South America to Africa... no way to tell with this photo.
... Its impossible!
Why are MAPS better
Maps are portable
More detailed
Better for everyday use
Cheaper
More flexible
Why are Globes better
Better Model
No Distortion