Cartographers use lines of latitude and longitude on an imaginary grid to locate points on Earth. Latitude lines run parallel to the equator and measure distances north and south. Longitude lines measure distances east and west from the prime meridian. Latitude and longitude are measured in degrees, minutes, and seconds, with each degree of latitude covering approximately 111 km on Earth's surface.

1. Mapping: Latitude and Longitude
KHS Oceanography

2. Latitude and Longitude
• Cartographers use an imaginary grid of parallel
lines and vertical lines to locate points on Earth.
• The equator circles Earth halfway between the
north and south poles separating Earth into two
equal halves called the northern hemisphere
and the southern hemisphere.

3. Latitude
 Lines of latitude are lines running parallel to the equator.
• Latitude is the distance in degrees north or south of the
equator.

4. Latitude
 Latitude is thus measured from 0° at the equator
to 90° at the poles.
• Locations north of the
equator are referred to
by degrees north
latitude (N).
• Locations south of the
equator are referred to
by degrees south
latitude (S).

5. Degrees of Latitude
Latitude
– Each degree of latitude is equivalent to about
111 km ( ) on Earth’s surface. 1° = 70 miles
– To locate positions on Earth more precisely,
cartographers break down degrees of latitude into
60 smaller units, called minutes (´). 1' = 1.2 miles
– A minute of latitude can be further divided into
seconds (´´). 1" = .02 miles
– Longitude is also divided into degrees, minutes,
and seconds.

6. Longitude
 To locate positions in east and west directions,
cartographers use lines of longitude, also known as
meridians.
• Longitude is the distance
in
degrees east or west of
the
prime meridian.
• The prime meridian,
representing 0°
longitude, is the
reference point for
longitude.

7. Longitude
 Points west of the prime meridian are numbered from 0°
to 180° west longitude (W).
• Points east of the prime meridian are numbered from 0°
to 180° east longitude (E).