1. Understanding
Longitude
and
Latitude
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Mr Thompson – Earth Science

2. Typical Graph
This is an example
of a typical graph
we are all familiar
with
The graph is made
up of different
“points” with lines
that connect
the points
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Mr Thompson – Earth Science

3. Typical Graph Y axis
Each point has two
values:
The “X” value that
runs along the
horizontal “X” axis
The “Y” value that
runs along the
X axis
vertical “Y” axis
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Mr Thompson – Earth Science

4. Y (3,8)
Typical Graph
(9,5)
X value is always
X
(0,0)
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Mr Thompson – Earth Science

5. A point can also have
Typical Graph negative (-) values
Y Negative X values
(0,0) are to the left of the
(-X, origin (0,0)
+Y) (+X,+Y)
X Negative Y values are
(-X,-Y) (+X,-Y) below the origin
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Mr Thompson – Earth Science

6. A point can also have
Typical Graph negative
Y (-) values
(-X,+Y) (+X,+Y)
Negative X values
are to the left
(0,0) of the origin (0,0)
(-X,-Y) (+X,-Y) X Negative Y values
are below the
origin
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Mr Thompson – Earth Science

7. East West, North Let the X axis be the
South on The Equator.
Earth Let the Y axis be the Prime
Y Meridian that runs through
Geeenwich outside of
London.
X
Lat/Long are the 2 grid
points by which you can
locate any point on earth.
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Mr Thompson – Earth Science

8. East West, North South on the Earth
N Let each of the
four quarters then
be designated by
W E North or South
and East or West.
S
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Mr Thompson – Earth Science

9. East West, North South on the Earth
The N tells us we’re
(N, W) (N, E) north of the Equator. The
S tells us we’re south of
the Equator.
The E tells us that we’re
east of the Prime
Meridian. The W tells us
that we’re west of the
(S, W) (S, E) Prime Meridian.
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Mr Thompson – Earth Science

10. East West, North South on the Earth
(N, W) That means all
points in North
America will have a
North latitude and a
West longitude
because it is North of
Prime Meridian the Equator and West
of the Prime Meridian.
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Mr Thompson – Earth Science

11. East West, North South on the Earth
What would be
the latitude and
longitude
directions in
Australia?
Prime Meridian ?
If you said South and East , you’re right!
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Mr Thompson – Earth Science

12. Latitude is the distance from
What is Latitude? the
equator along the Y axis.
90°N
Y
All points along the equator
have a value of 0 degrees
latitude.
X
North pole = 90°N
South pole = 90°S
Values are expressed in terms
90°S of degrees.
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Mr Thompson – Earth Science

13. 90°N
Y What is Latitude?
Each degree of
latitude is divided into
X 60 minutes.
Each minute is
divided into 60 seconds.
90°S
This is also true of longitude.
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Mr Thompson – Earth Science

14. What is Latitude?
90°N For Example:
Y
37°, 02’,51’’N
X
This is close to
the latitude
90°S where you live.
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Mr Thompson – Earth Science

15. What is Longitude?
Longitude is the distance
Y
from the prime meridian along
the X axis.
All points along the prime
X
meridian have a
value of 0 degrees longitude.
The earth is divided into two
parts, or
hemispheres, of east and
180°W 180°E west longitude.
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Mr Thompson – Earth Science

16. What is Longitude?
Y
The earth is divided into
360 equal slices
X (meridians)
180 west and 180 east
of the prime meridian
180°W 180°E
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Mr Thompson – Earth Science

17. What is Latitude?
90°N Our latitude and
Y
longitude might be:
X 38.25° N
76.96° W
90°S
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Mr Thompson – Earth Science

18. So Where is (0,0)?
The origin point (0,0)
is where the equator
intersects the
prime meridian.
(0,0) is off the western
coast of Africa in the
Atlantic Ocean.
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Mr Thompson – Earth Science

19. See If You Can Tell In Which Quarter
These Lon/Lats Are Located
1. 41°N, 21°E
2. 37°N, 76°W
A B 3. 72°S, 141°W
4. 7°S, 23°W
C D 5. 15°N, 29°E
6. 34°S, 151°E
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Mr Thompson – Earth Science

20. 1. B
2. A
3. C
5. B
4. C
6. D
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Mr Thompson – Earth Science

21. See if you can find
those same
latitude/longitude
locations on a map!
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Mr Thompson – Earth Science

22. Positioning on the Earth’s Surface
East is the direction of Latitude: (90oN to 90oS)
rotation of the Earth North Pole
Prime Meridian Longitude: (180oE to 180oW)
0o Longitude
Tropic of Cancer Latitude 23½o North
21st June 60EW
90oE
3060ooW o
9030oW
E
o oo
9066½ o
22nd Sept 23½
Equator Latitude 0o
20 March
th 900 23½o
22nd December
Tropic of Capricorn Latitude 23½o South
Longitude 90o West
Longitude 90oEast
Longitude 60o West Longitude 60o East
Longitude 30o West Longitude 30o East
South Pole 22
Latitude and Longitude together enable the fixing of position on the Earth’s surface.

23. Now you’re ready to find some locations on a map!
Review At
www.ScienceByThompsom.com
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Mr Thompson – Earth Science