Latitude is the angular distance north or south from the equator.
Assuming the Earth to be a sphere (although
it is more nearly an oblate spheroid),
we can think of the latitude of a point as the angle between a line from the center of the Earth to the point and a line from
the center to the equator at the same longitude.
Each pole, then, has a latitude of 90°, and so latitude is measured
from 0° to 90° north and south of the equator, lines of
latitude being circles parallel to the equator that get progressively
smaller toward the poles. Each degree of latitude is about 111 km (69 miles).
|Parallels of latitude are circles on the surface
of the Earth, parallel to the equator and labeled according to their
angular distance from the equator. The position of a place on the
surface of the Earth can be specified by citing the parallel of latitude
and the meridian of longitude which intercept at that place. Here,
the coordinates of P are 40°N 60°W, a position in the North
Atlantic Ocean some 1,200 km east of New York
|Simplified diagram of latitude and
longitude. Image: NASA
The Tropic of Cancer and Tropic
of Capricorn are 23.5°C away from the equator, and the Arctic and
Antarctic circles are at 66.5°C, which is 23.5°C away from the poles.
For celestial latitude see celestial