A Typical Graph
hThis is an example of a typical graph we are all familiar with.
hThe graph is made up of different “points” with lines that connect the points.
A Typical Graph
hEach point has two values indicating place:
hThe “X” value that runs along the horizontal “X” axis
hThe “Y” value that runs along the vertical “Y” axis
Y axis
X axis
A Typical Graph
hX value is always stated first, followed by the Y value
hThe “origin” is the point where the two axes intersect with a value of (0,0)
(0,0)
(3,8)Y
X
(9,5)
Typical Graph
hA point can also have a negative (-) value
hNegative X values are to the left of the origin (0,0)
hNegative Y values are below the origin
X
Y
(-X,+Y)
(+X,-Y)
(+X,+Y)
(-X,-Y)
(0,0)
East West, North South on the Earth
•The X axis is the equator.
hThe Y axis is the prime meridian that runs through Greenwich, England.
hLat/Long are the two grid points by which one can locate any point on Earth.
Y
X
East West, North South on the Earth
hLet each of the four quarters (quadrants) then be designated by North or South and East or West.
N
S
EW
East West, North South on the Earth
hThe N tells us we’re north of the equator. The S tells us we’re south of the equator.
hThe E tells us that we’re east of the prime meridian. The W tells us that we’re west of the prime meridian.
(N, W) (N, E)
(S, W) (S, E)
East West, North South on the Earth
hAll points in North America will have a North latitude and a West longitude because it is North of the equator and West of the prime meridian.
(N, W)
Prime Meridian
East West, North South on the Earth
hWhat would be the latitude and longitude directions in Australia?
Prime Meridian ?
If you said South and East , you’re right!
What is Latitude?hLatitude is the
distance from the equator along the Y axis.
hAll points along the equator have a value of 0 degrees.
hNorth pole = 90°N
hSouth pole = 90°S
hAll values are in stated in degrees.
Y
X
90°S
90°N
What is Latitude?
hEach degree of latitude is divided into 60 minutes.
hEach minute is divided into 60 seconds.
Y
X
90°S
90°N
This is also true of longitude.
What is Latitude?
hFor example,
h40° 02’ 51’’N
hThis is close to the latitude where you live.
Y
X
90°S
90°N
And Longitude? hLongitude is the distance from the prime meridian along the X axis.
hAll points along the prime meridian have a value of 0 degrees longitude.
hEarth is divided into two parts, or hemi-spheres, of east and west longitude.
Y
X
180°W 180°E
Meridians and Parallels?
hEarth is divided into 360 equal N-S slices (meridians)
-180 west and 180 east of the prime meridian
hEarth is divided into 180 equal E-W slices (parallels)
-90 north and 90 south of the equator
Y
X
180°W 180°E
Meridians and Parallels?
hMeridians of longitude run N and S, but are used to measure E and W.
hParallels of latitude run E and W, but are used to measure N and S
What is our location?
hCentral Peoria’s latitude and longitude are approximately:
h40°, 44’, 24’’N
h89°, 36’, 36’’W
Y
X
90°S
90°N
So Where is (0,0)?
hThe origin point (0,0) is where the equator intersects the prime meridian.
hPoint (0,0) is off the western coast of Africa in the Atlantic Ocean.
In which quadrants are the following latitudes and longitudes?
h1. 41°N, 21°E
h2. 37°N, 76°W
h3. 72°S, 141°W
h4. 7°S, 23°W
h5. 15°N, 29°E
h6. 34°S, 151°E
A B
C D
Equator Latitude 0o
Latitude: (90oN to 90oS)
Latitude 23½o NorthTropic of Cancer
Latitude 23½o SouthTropic of Capricorn
Longitude 30o East
Longitude 60o East
Longitude 30o West
Longitude 60o West
Positioning on the Earth’s SurfaceEast is the direction of rotation of the Earth North Pole
South Pole
23½o 23½o
66½o 90o
900
21st June
22nd December
22nd Sept
20th March
30oE60oE90oE90oW30oW60oW
Longitude 90oEastLongitude 90o West
Prime Meridian
0o Longitude
Longitude: (180oE to 180oW)
Latitude and Longitude together enable the fixing of position on the Earth’s surface.