Latitude, Longitude, and
Time Zones
Typical Graph
This is an example of a typical graph.
It is made up of points that are connected by a line.
Typical Graph
Y axis
X 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...
(4,7)
and...
Typical Graph
X Y (-X,+Y) (+X,-Y) (+X,+Y) (-X,-Y)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.
Now let’s apply the same principles to latitude and longitude.
90°S
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.
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)
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°
0°
And if you go half way
around the world you will reach the 180° longitude line.
180° 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.
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
Any location north of the equator is a NORTH LATITUDE
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
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
60°N, 30°W
What are the coordinates of location...B
15°S, 105°W
What are the coordinates of location...C
75°S, 75°E
Let’s look at Ithaca, NY, the home of Cornell University.
Ithaca
The latitude is more than 42°N
42°N
but less than 43°N
43°N
and the longitude is more than 76°W
76°W
but less than 77°W
77°W
We need to be more precise. We can do that by subdividing each degree into 60 smaller units called minutes.
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.
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.
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.
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!)
MNEMONIC “Head for the HILLSS”: High-Low Latitude,
LONGITUDE AND LATITUDE
LONGITUDE LATITUDE MERIDIAN EQUATOR DEGREESWhy is an accurate system of time
so important in our world?
TRAVEL and
TRANSPORTATION
COMMUNICATIONS
FINANCE
???
I = PR
T
INTERNATIONAL DATE LINE
Why the zigzag line?
SUNDAY MONDAY
MNEMONIC
TIME ZONES
In recent years it is becoming more common to use the more accurate Coordinated Universal Time (abbreviated as UTC) which uses an atomic time clock to regulate world time. UTC at the prime meridian is used as a starting point to determine time worldwide.
Time zones are measured by reference to a specific point, namely the prime meridian which runs through Greenwich, England. The time at the prime meridian is referred to as
Greenwich Mean Time -- GMT
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 4:00 PM in that country.
Note-taking tip…
Key term on leftFollowed by a dash – then paraphrase
There are
24*
primary world time zones
Each time zone spans approximately 15 degrees of longitude * Because of local and political considerations there are
WORLD CLOCK
UTC-ZULU* time?
If it’s 12:00 PM GMT or UTC-ZULU time, what is the time in Los Angeles? In Ankara, Turkey?
*Used by the military and others to indicate GMT time at the 0° meridian (prime meridian)
It’s all the SAME!
So what time is it in…
OSLO, Norway? (UTC+1) = BOMBAY, India? (UTC+5) = CHICAGO? (UTC-6) =
LOS ANGELES? (UTC-8) =
See page 25 in your NWAt
UTC-0 time is now 2:00 PM
GMT = 2:00 PM UTC = 2:00 PM
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.
US TIME ZONES
ABBREVIATIONS
• EST
• EDT*
• CST
• CDT*
• MST
• PST
• AST
24-Hour Time
•Often referred to as MILITARY or RAILROAD time. •Based on 24-hour day
12:05 AM = 00:05 1:00 AM = 01:00 2:00 AM = 02:00 2:45 AM = 02:45 7:30 AM = 07:30 12:00 PM = 12:00 1:00 PM = 13:00 8:30 PM = 16:30
WHAT TIME IS IT?
(1) 3:30 AM = (2) 2:00 PM = (3) 11:20 AM = (4) 7:52 PM = (5) 11:59 PM = (6) 12:15 AM = (7) 12:15 PM =
MONDAY SUNDAY
11:59PM
12:00AM
Back to the
INTERNATIONAL DATE LINE (IDL)
What day is it here?
MNEMONIC