Latitude
&
Longitude
Latitude and Longitude
• Latitude and Longitude are measure in
DEGREES AND MINUTES
Xo Y ‘
Degrees
Minutes
There are 60 minutes in one degree
Examples:
Latitude  30o45’ N
Longitude  46o12’ E
Latitude
• The distance in degrees,
north or south of the equator.
- North Pole = 90o N
- Equator = 0o
- South Pole = 90o S
• The equator is the reference line for latitude.
• If you draw a line from the equator to the center of
the Earth and then to where a person is standing,
the angle between the two lines is the persons
latitude.
Latitude
49o
Latitude lines are also called PARALLELS
because they run parallel to the equator.
Latitude
• At night in the
Northern Hemisphere,
latitude can be
determined by
measuring the altitude
of Polaris (North Star)
To Polaris
To Polaris
90°
40°
To Polaris
0°
Horizon
North
Pole
Longitude
• Based on the Sun’s Apparent motion
through the sky.
• How long does it take the Earth to rotate
once on its axis?
» 24 hours
• How many degrees does it rotate in this
time?
» 360o
• Degrees per hour = 360/24 = 15o/hour
Longitude
• The distance, in
degrees, measured
east or west of the
Prime Meridian.
• Prime Meridian
passes through
Greenwich, England
(Longitude 0o)
Longitude
• As you travel east or
west from the Prime
Meridian, longitude
increases until it
reaches 180o ( The
International Date
Line)
Measuring Longitude
• Greenwich Mean Time (GMT)
– what time it is in Greenwich, England
– 0o line for longitude
• Solar Time – (noon)
– when the sun reaches it highest altitude in
the sky at your location.
Measuring Longitude
• Remember – the Earth rotates at 15o/hr
and that the Sun “appears” to move
through the sky at the same rate.
• If you know what time it is in Greenwich
when it is noon at your location you can
calculate your longitude.
Measuring Longitude
• It was 2:00 pm in
Greenwich (GMT) when
it was noon at your
location (12:00pm)
• Time Difference =?
2 hours
• 2 hours X 15o/hr
= 30o
• Your longitude = 30oW
Note –
  Earth Rotates from W to E  
If it is NOON your time and GMT = PM, you are WEST of the P.M.
If it is NOON your time and GMT = AM, you are EAST of the P.M.
Writing Latitude & Longitude
• Latitude (N or S) comes FIRST, followed
by the longitude (E or W)
45o N, 33o E
85o S, 123o W
95o S, 47o E
Anything WRONG here!!
N
o
r
t
h
S
o
u
t
h
Latitude
Longitude
•line running east to west
•measures the distance in
degrees North and South of
the equator.
-measured by parallels,
because all lines of latitude
are parallel.
-largest value of latitude is
90°
-line running north to south
-measures the distance in
degrees East and West
of the prime meridian.
-All meridian lines meet at
the poles and are further
apart at the equator. They
are not parallel
-largest value of longitude is
180°
-
Equator – 0°00’ N/S
North Pole – 90°00’ N
South Pole – 90°00’ S
Horseheads, NY – 42°10’N
-Prime Meridian – 0°00’ E/W
Horseheads, NY – 76°51’ W
+
60
West
45
30
15
0
15
East
30
45
15 o/hr
30
N
o
r
10 t
h
20
equator
0
10 S
o
20 u
t
h
30
Prime
Meridian
What is the latitude and longitude of the ship?
60
West
45
30
15
0
10o N, 45o W
15
East
30
45
30
N
o
r
10 t
h
20
equator
0
10 S
o
20 u
t
h
30
Prime
Meridian
What is the latitude and longitude of the ship?
60
West
45
30
15
0
15o S, 35o E
15
East
30
45
30
N
o
r
10 t
h
20
equator
0
10 S
o
20 u
t
h
30
Prime
Meridian
If it is noon at your location and 3 p.m.
GMT, what is your longitude?
West
60
45
30
15
45o W
3 hours x 15o/hr
PM = West
0
15
East
30
45
30
N
o
r
10 t
h
20
equator
0
10 S
o
20 u
t
h
30
Prime
Meridian
If it is noon at your location and 10 a.m.
GMT, what is your longitude?
West
60
45
30
15
30o E
2 hours x 15o/hr
AM = East
0
15
East
30
45
30
N
o
r
10 t
h
20
equator
0
10 S
o
20 u
t
h
30
Prime
Meridian
If it is noon at your location and 2 p.m.
Latitude = 20o N - Duh – North Star
Proper
written
formatof=Polaris
20o N,is30
GMT, and
the altitude
20ooW
, what Longitude = 30o W 2 hours x 15o/hr
is your latitude and longitude?
PM = West
60
45
30
15
0
15
30
45
West
East
30
N
o
r
10 t
h
20
Noon
2 PM
equator
0
Earth’s Rotation
Prime
Meridian
10 S
o
20 u
t
h
30
Latitude = 15o N - once again - Duh
Longitude = 45o E 3 hours x 15o/hr
If it is noon at you location and 9 a.m. GMT,
o N,o 45o E
Proper
= 15
and thewritten
altitudeformat
of Polaris
is 15
, what is
your latitude and longitude?
60
45
30
West
15
0
15
30
45
AM = East
East
30
N
o
r
10 t
h
20
equator
0
10 S
o
20 u
t
h
30
Prime
Meridian
ESRT