Unnderstanding Longitude & Latitude

A 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.

A Typical Graph Each point has two values indicating place: Y axis Each point has two values indicating place: The “X” value that runs along the horizontal “X” axis The “Y” value that runs along the vertical “Y” axis X axis

X value is always stated first, followed by the Y value A Typical Graph X value is always stated first, followed by the Y value The “origin” is the point where the two axes intersect with a value of (0,0) Y (3,8) (9,5) X (0,0)

A point can also have a negative (-) value Typical Graph A point can also have a negative (-) value Negative X values are to the left of the origin (0,0) Negative Y values are below the origin Y (-X,+Y) (+X,+Y) (0,0) X (-X,-Y) (+X,-Y)

East West, North South on the Earth The X axis is the equator. The Y axis is the prime meridian that runs through Greenwich, England. Lat/Long are the two grid points by which one can locate any point on Earth. Y X

East West, North South on the Earth Let each of the four quarters (quadrants) then be designated by North or South and East or West. W E S

East West, North South on the Earth The N tells us we’re 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 prime meridian. (N, W) (N, E) (S, W) (S, E)

East West, North South on the Earth (N, W) All 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. Prime Meridian

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!

Latitude is the distance from the equator along the Y axis. All points along the equator have a value of 0 degrees. North pole = 90°N South pole = 90°S All values are in stated in degrees. What is Latitude? 90°N Y X 90°S

This is also true of longitude. What is Latitude? 90°N Each degree of latitude is divided into 60 minutes. Each minute is divided into 60 seconds. Y X 90°S This is also true of longitude.

This is close to the latitude where you live. What is Latitude? 90°N For example, 40° 02’ 51’’N This is close to the latitude where you live. Y X 90°S

Longitude is the distance from the prime meridian along the X axis. And Longitude? Longitude is the distance from the prime meridian along the X axis. All points along the prime meridian have a value of 0 degrees longitude. Earth is divided into two parts, or hemi- spheres, of east and west longitude. Y X 180°W 180°E

Meridians and Parallels? Earth is divided into 360 equal N-S slices (meridians) 180 west and 180 east of the prime meridian Earth 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? Meridians of longitude run N and S, but are used to measure E and W. Parallels of latitude run E and W, but are used to measure N and S

Central Peoria’s latitude and longitude are approximately: What is our location? 90°N Central Peoria’s latitude and longitude are approximately: 40°, 44’, 24’’N 89°, 36’, 36’’W Y X 90°S

So Where is (0,0)? The origin point (0,0) is where the equator intersects the prime meridian. Point (0,0) is off the western coast of Africa in the Atlantic Ocean.

In which quadrants are the following latitudes and longitudes? 1. 41°N, 21°E 2. 37°N, 76°W 3. 72°S, 141°W 4. 7°S, 23°W 5. 15°N, 29°E 6. 34°S, 151°E A B D C

Let’s see how well you did... 1. B 2. A 3. C 4. C 5. B 6. D

In Summary!

Positioning on the Earth’s Surface East is the direction of rotation of the Earth Equator Latitude 0o Latitude: (90oN to 90oS) North Pole South Pole Prime Meridian 0o Longitude Longitude: (180oE to 180oW) Longitude 60o West Longitude 30o West Longitude 60o East 90o Longitude 30o East 66½o Latitude 23½o North Tropic of Cancer 23½o 21st June 22nd December 22nd Sept 20th March 90oW 60oW 30oW 90oE 30oE 60oE 23½o 900 Latitude 23½o South Tropic of Capricorn Longitude 90o West Longitude 90oEast Latitude and Longitude together enable the fixing of position on the Earth’s surface.

Now you are ready to find some locations on a map!