Distortions in Map Projections

projection

Equirectangular

location

zero base

diameter

5°

15°

degrees of rotation around:

horizontal axis

0

15

30

45

60

75

90

vertical axis

0

30

60

90

120

150

180

current North Pole

-180

-150

-120

-90

-60

-30

0

30

60

90

120

150

180

All map projections give rise to certain distortions. This Demonstration shows these distortions for different projections by applying three sequential rotations to the globe: the first is about the

y

axis, the second is about the

z

axis, and the third is about the North Pole after the first two rotations.

To better evaluate map distortion, N. A. Tissot imagined an (infinitesimally) small circle (indicatrix) centered on some point on the surface of the Earth and considered its shape after transformation by a given map projection. This Demonstration also shows Tissot's indicatrix for selected locations, for different projections and for different rotations of the globe.