Cartography Word of the Day: Conformal

North and South America in the Lambert Conformal Conic Projection (courtesy Map Projections Gallery)

Next in our irregular series.

This edition of the Word of the Day focuses on one of the defnining aspects of projections, the art and science of representing the globe of the world meaningfully on a flat surface. This can’t be done accurately, of course, but degrees of accuracy can be represented depending on approach.

On way to describe a map is “conformal”. The root of the word’s meaning is obvious; but in the case of a map (such as the excerpted map illustration here), it’s doesn’t conform exactly. Erwin Raisz, in General Cartography, defines conformality thus:

The part of the map is very illustrative of that point. While all shapes seem to be more or less correct, the projection forces certain distortions to obey that attribute. North America seems smaller than it should be, and South America is quite enlarged.

The cheif use of conformal projections is in navigation, since they are good at showing directions, due to the properties cited by Raisz above.