1. Latitude, Longitude, and Time Zones

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: (4,7)
Y axis
Each point has two values:
(4,7)
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. 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
And 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 (or anywhere else)

6. What is longitude?
Longitude is the distance
from the prime meridian
along the X axis.
Just like latitude, longitude
is measured in degrees.
The prime meridian is 0°
And if you go half way
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. It’s the SAME line.
What is the maximum possible longitude on Earth?
180° is the maximum possible longitude on Earth.

7. 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
* A MERIDIAN is another name for a line of longitude

8. Where do most people on earth live?
Any location north of the equator is a NORTH LATITUDE
Where do most people on earth live?

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

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

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

12. We can divide the Earth into quadrants: NW where all
latitudes are NORTH and all longitudes are WEST.
Notice that EVERY point in the United States will have a NORTH
latitude and a WEST longitude since we are in the NW quadrant.

13. 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! (It’s the x coordinate)
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?

14. 43°N
Let’s look at Ithaca, NY, the home of Cornell University.
The latitude is more
than 42°N
77°W
76°W
but less than 43°N
and the longitude is
more than 76°W
but less than 77°W
Ithaca
42°N
We need to be more precise. We can do that by subdividing each degree into 60 smaller units called minutes.

15. 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.
See these 2 marks?
They are half way
(30’) between
42°N and 43°N.
Using a ruler,
connect them.
The line you just drew is 42°30’N. Now let’s look at lines of longitude.
See these 2 marks?
They are half way (30’) between 76°W and 77°W.
Using a ruler, connect them.
The line you just drew is 76°30’W.
Now let’s see if we can locate Ithaca more precisely.

16. First comes latitude.
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.
Now we’ll do longitude which, for Ithaca is easy since it’s located right on the 76°30’W line. 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.

17. 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.
> Most of the time it will be impossible to be absolutely precise. Your best estimate might have to be to the nearest 5 or 10 minutes. In other words, an estimate of 73°25’W is OK but 73°28’W is trying to be more accurate than is reasonably possible.

18. Degrees and minutes Here is how you write degrees and minutes…
40° 32’N (latitude)
10° 43’W (longitude)
TOGETHER> 40°32’N, 10°43’W
Latitude is always given first, followed by longitude.
Typing tip: for the degree symbol, ALT-0176 (Try it!)

19. LONGITUDE AND LATITUDE
EQUATOR
LONGITUDE
DEGREES
MERIDIAN

20. PRIME MERIDIAN

21. INTERNATIONAL DATE LINE
The ceremony of Crossing the Line is an initiation rite in the Royal Navy, U.S. Navy, U.S. Coast Guard, U.S. Marine Corps, and other navies that commemorates a sailor's first crossing of the Equator.1 Originally, the tradition was created as a test for seasoned sailors to ensure their new shipmates were capable of handling long rough times at sea. Sailors who have already crossed the Equator are nicknamed (Trusty) Shellbacks, often referred to as Sons of Neptune; those who have not are nicknamed (Slimy) Pollywogs.
Why the zigzag line?

22. TIME ZONES
Time zones are measured by reference to a specific point, namely the prime meridian which runs through Greenwich, England. We have commonly referred to time at this point as Greenwich Mean Time -- GMT
In recent years it has been common to refer to the more accurate Coordinated Universal Time (abbreviated as UTC) which uses an atomic time clock to regulate world time. UTC is used as a starting point to determine time in other countries worldwide.
So, for example, if a country is stated as having the time UTC+3, this means that when it is 1:00 PM in Greenwich, it is 4pm in that country.

23. There are 24* primary world time zones
Each time zone spans approximately 15 degrees of longitude
* Because of local and political considerations there are actually more than 24 officially recognized time zones

24. WORLD CLOCK

25. UTC time?

26. JET LAG?
Many travelers find that they suffer from a condition known as 'jet lag' when they have crossed time zones.
This is a physiological condition triggered by the body becoming out of sync with the usual light and dark patterns to which it is accustomed.
The condition is characterized by numerous symptoms, such as extreme fatigue, disorientation and loss of appetite.
Jet lag often takes many days to recover; a rough medical guideline being one day per time zone. Sleep is seen as one of the best cures for jet lag, as is exposure to sunlight.

27. US TIME ZONES

28. FOUR US TIME ZONES

29. ABBREVIATIONS
EST
EDT
CST
MST
PST
AST
HST

30. So what time is it right now in…
LONDON, England?
PARIS, France?
BOMBAY, India?
CHICAGO?
LOS ANGELOS?
LAS VEGAS?
See page 25 in your NWAt