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