1. Latitude and Longitude:
Finding Locations on
Planet Earth.
With thanks and credit to Step.com

2. Typical Graph This is an example of a typical graph.
It is made up of points
that are connected by
a line.

3. Typical Graph Each point has two values: An ‘X’ value that runs along
(4,7)
Y axis
Each point has two values:
An ‘X’ value that runs along
the horizontal ‘X’ axis and
A ‘Y’ value that runs along
the vertical ‘Y’ axis
Each point is expressed as an X value and a Y
value with the X value written first. For example...
X axis
and
(7,5)

4. Typical Graph Graphs may be divided into quadrants with the
X and Y values being
either positive (+) or
negative (-) depending
on the quadrant in which
they are located. Y
(-X,+Y)
(+X,+Y) X
Now let’s apply the same
principles to latitude and
longitude.
(-X,-Y)
(+X,-Y)

5. On the map horizontal lines
are lines of latitude and....
vertical lines are lines of
longitude.
The X axis is the equator
and the Y axis which runs
through Greenwich, England
is the Prime Meridian.
Equator
Prime Meridian

6. Any location north of the equator is a NORTH LATITUDE

7. Any location south of the equator is a SOUTH LATITUDE

8. Any location west of the prime meridian is a WEST LONGITUDE

9. Any location east of the prime meridian is an EAST LONGITUDE

10. We can divide the Earth into quadrants: NE where all
latitudes are NORTH and all longitudes are EAST.

11. We can divide the Earth into quadrants: SE where all
latitudes are SOUTH and all longitudes are EAST.

12. We can divide the Earth into quadrants: SW where all
latitudes are SOUTH and all longitudes are WEST.

13. We can divide the Earth into quadrants: NW where all
latitudes are NORTH and all longitudes are WEST.

14. 90°N
What is latitude?
Latitude is the distance
from the equator along the
Y axis.
It is expressed in degrees.
The north pole is 90° N
The south pole is 90° S
Remember that the
equator is 0° latitude.
90°S 0°
What is the maximum possible latitude on Earth?
90° is maximum. You could be at 90°N or 90°S but
there is no greater latitude on Earth

15. What is longitude?
Longitude is the distance from the prime meridian along the X axis.
The prime meridian is 0°
If you go halfway around the world you will reach the 180° longitude line.
180° 0°
180°
Understand that there aren’t two 180° lines. On this FLAT
map it just looks that way. Its the SAME line.
What is the maximum possible longitude on Earth?
180° is the maximum possible longitude on Earth.

16. What are the coordinates of location......A
60°N, 30°W
75°S, 75°E
15°S, 105°W
Each box on this map is 15°. With that in mind how can we identify specific locations
(red dots)? Remember, write latitude first!
What are the coordinates of location......A
What are the coordinates of location......B
What are the coordinates of location......C
But what about location D ? It’s in the middle of a box. What do we do now?

17. Each degree is about 111 kilometers so the yellow-shaded
43°N
Look at Ithaca, NY.
77°W
76°W
The latitude is more
than 42°N
but less than 43°N
and the longitude is
more than 76°W
but less than 77°W
Ithaca
42°N
Each degree is about 111 kilometers so the yellow-shaded
box (1° x 1°) in which Ithaca is located covers over 12,000
square kilometers of land.
We need to be more precise. We can do that by subdividing
each degree into 60 smaller units called minutes.

18. If there are 60
minutes in each
degree then half
a degree would
be 30 minutes.
Let’s draw in the
30 minute (30’)
line.
The line you just drew is 42°30’N. Now let’s look at lines of longitude.
The line you just drew is 76°30’W.
Now let’s see if we can locate Ithaca more precisely.

19. Notice that Ithaca is
just south of the
42°30’N line. If it’s
not quite 30’ then
let’s call it 25’.
Ithaca is located
42°25’N.
Ithaca’s longitude is 76°30’W.
Now we’ll put latitude and longitude together to give a precise location:
Ithaca is 42°25’N , 76°30’W.

20. Plattsburgh is about 44°40’N, 73°25’W.

21. SO PRACTICE, PRACTICE, PRACTICE!
Here are some things to remember:
> Latitude is written first and must always include N (north) or S (south) of the
equator.
> Longitude is written next and must always include E (east) or W (west) of
the prime meridian.
> Each degree of latitude or longitude can be divided into 60 minutes.
> A minute, as used here, is a unit of distance on the earth’s surface. It is
not a unit of time.
> As with anything else you learn you will get better with practice
SO PRACTICE, PRACTICE, PRACTICE!