Latitude and
Longitude
Introduction
There are many methods that can be used to
locate a position on the surface of the earth:
• Landmarks and features on the earth’s surface
– may not provide enough detail to find an exact
location.
– Difficult to use in the open ocean
• Latitude and longitude
– Uses a grid system
– Created by the Greeks
Latitude
• Latitude defines location in terms of
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north or south.
Latitude lines are also known as
parallels because they make a full
circle around the earth and never touch
(they are parallel).
*Zero degrees latitude is known as the
Equator.
All points North of the Equator have
North latitudes, all points South of the
Equator have South latitudes.
The maximum number of degrees
latitude that can be present on earth’s
surface is 90o
– *North Pole = 90o North Latitude
– *South Pole = 90o South Latitude
Distance of Latitude
• Degrees of latitude actually equal a certain
distance.
– One degree of latitude = approximately 60 miles.
• Miles are called minutes when used in
latitude/longitude coordinates.
– Minutes are like fractions of one degree
– 42o; 52’ N = 42 degrees, 52 minutes North
Longitude
• Longitude defines a position on the planet in terms of east or
west.
• Lines of longitude are also known as meridians
• Longitude lines form half-circles that go from the north to the
south pole and do not encircle the whole planet.
• The *prime meridian (zero degrees longitude) is drawn
from the north to the south pole.
– It goes through the city of Greenwich, England
• The *180o meridian is called the International Date Line
Distance of Longitude
• Meridians are not parallel, so the distance
between them is different at the equator versus
the north/south poles.
Important lines:
• Latitude:
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Equator = 0o latitude ( ___ )
North Pole = 90o N
South Pole = 90o S
Tropic of Cancer 23o N
Tropic of Capricorn 23o S
Arctic Circle 66o N
Antarctic Circle 66o S
• Longitude:
– Prime Meridian = 0o longitude ( | )
– International date line = 180o
longitude