Standard parallel
Topic: Map Projections · NCERT: Class 11, Ch 4 "Map Projections"
Meaning
A standard parallel is the parallel along which a cone touches the globe in a conical projection. Along this line the map's scale is exactly true. The farther a place is from the standard parallel, the more it is distorted. Mapmakers therefore pick a standard parallel through the middle of the area they want to show.
Example
In NCERT's construction of a simple conical projection for the area from 10°N to 70°N and 10°E to 130°E (this covers India), the standard parallel is 40°N. Places near 40°N show the least distortion. Places near 10°N or 70°N show more.
Don't confuse with
- Central meridian: this is the middle meridian of the map (70°E in the same example), along which the parallels are spaced out. A standard parallel runs east-west. A central meridian runs north-south.
- Equator: this is the line a cylinder usually touches in a cylindrical projection. A standard parallel belongs to a cone.