Length of a degree of latitude and longitude
Topic: Latitude, Longitude and Time · NCERT: Class 11, Ch 3 "Latitude, Longitude and Time"
Meaning
A degree of latitude is about the same length everywhere, roughly 111 km. It is 110.6 km at the equator and 111.7 km at the poles. It is slightly longer at the poles because the earth is flatter there. A degree of longitude changes a lot. Meridians are farthest apart at the equator and meet at the poles. So a degree of longitude is 111.3 km at the equator, 79 km at 45° and 0 km at the poles.
Example
At the equator, as in Kenya, moving 1° east covers about 111 km. Along 45°N, which crosses northern Italy, the same 1° covers only about 79 km.
Don't confuse with
- "A degree of latitude is longest at the equator": this is a common trap and it is false. A degree of latitude is longest at the poles. It is the degree of longitude that is longest at the equator.