Earth and Space Science / Unit 1: Earth as a System
1.5 Maps and Map Skills
Notes
A map is a flat model of Earth. Flattening a sphere always causes some distortion.
- A map scale relates map distance to real distance. If 1 cm = 5 km, a trail 4 cm long is 20 km.
- A legend (key) explains symbols; a compass rose shows direction.
- Projections differ: a Mercator map keeps directions true but exaggerates the size of areas near the poles (Greenland looks huge).
- A globe shows shapes, areas and distances most accurately.
- Example: 7.5 cm on a map with scale 1 cm = 2 km is $7.5 \times 2 = 15$ km.
Practice
On a map, 1 cm represents 5 km. Two towns are 6.5 cm apart. The real distance is:
$6.5 \times 5 = 32.5$ km.
Why do all flat maps contain some distortion?
Projection of a sphere onto a plane changes size, shape, distance or direction.
On a Mercator map, regions near the poles appear:
Mercator stretches high latitudes.
Ready for more? Take the Unit 1 test.