Understanding Latitude & Longitude

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.

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

Typical Graph X value is always stated first Followed by the Y value The “origin” is the point where the 2 axes intersect with a value of (0,0) (3,8) (9,5) Y X (0,0)

Typical Graph A point can also have negative (-) values 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)

Equator and Prime Meridian 0o Longitude – Prime Meridian 0o Latitude - Equator Let the X axis be the Equator. Let the Y axis be the Prime Meridian that runs through Greenwich England Lat/Long are the 2 coordinate lines by which you can locate any point on Earth.

North, South, East and West on the Earth Let each of the four quarters then be designated by North or South and East or West.

North, South, East and West 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)

North, South, East and West on the Earth That means 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. What about New York? (N, W) Equator Prime Meridian

North, South, East and West on the Earth Equator What would be the latitude and longitude directions in Australia? ? Prime Meridian If you said South and East , you’re right!

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

What is Latitude? All latitude lines are parallel to the equator. Y All latitude lines are parallel to the equator. These lines are also called parallels. X 90°S

What is 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. The earth is divided into two parts, or hemispheres, of east and west longitude. Y X W E 180° 180°

What is Longitude? Longitude lines are also called meridians but are NOT parallel to each other. All longitude lines begin at the North Pole and end at the South Pole.

So how do we find a position on Earth? The latitude line is named first along with its compass direction Longitude is named next along with its compass direction For instance – “A” is 20oS, 100oE

See If You Can Tell In Which Quarter These Coordinates Are Located 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 You Did! 1. B 2. A 3. C 4. C 5. B 6. D

See if you can find those same latitude/longitude locations on a map!

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’re ready to find some locations on a map!