Presentation on theme: "Longitude and Latitude"— Presentation transcript:
1 Longitude and Latitude Earth is divided into imaginary lines of longitude and latitude measured in degrees (since Earth is spherical). These lines form Earth’s coordinate system and enable us to locate any position on Earth’s surface.
2 DirectionsCompass = tool that uses Earth’s magnetic field to locate magnetic NorthLabel the compass rose with the appropriate directionsNWNEWESESWS
3 LatitudeImaginary lines that run horizontally (east-west) across globe“Ladder-tude” = look like rungs of a ladderAlso called parallels because equal distances from each otherNorth Pole = 90⁰N Latitude (max latitude)South Pole = 90⁰S Latitude (max latitude)Equator = 0⁰ Latitude Divides planet into Northern and Southern HemispheresLatitude in the Northern hemisphere is determined by the altitude of the North Star, Polaris.
4 Lines of Latitude Tropic of Cancer 23.5° N. Equator Tropic of Capricorn23.5° S.
5 Finding Polaris and Ursa Minor To find the star Polaris and the constellation Ursa Minor, locate the two end stars in the cup of the "Big Dipper."Connect a line through these two stars. This will point to the star Polaris.Polaris is in the constellation Ursa Minor. Ursa Minor is better known as the "Little Dipper."Polaris will not be an extremely bright star, but it will be located due North.
6 LongitudeImaginary lines that run vertically (north-south) across globeConverge at the poles and are widest apart at the equatorAlso called meridiansPrime Meridian = 0⁰ Longitude – runs through Greenwich, EnglandInternational Date Line = 180⁰ Longitude in Pacific Ocean (max longitude)
8 To find the difference in hours between local time and Greenwich time: Multiply the difference by 15° per hour (The rate at which the Earth rotates)If local time is earlier than Greenwich time, then your position is West Longitude.If local time is later than Greenwich time, then your position is East Longitude.
9 ExampleThere is a 5 hour time difference between New York City and Greenwich, England. What is the longitude of NYC? (Local Time in NYC is earlier than Greenwich)Step 1: What is the time difference? _______Step 2: Multiply difference by 15⁰: _______Step 3: West or East? _________Answer: __________5 hrs5 x 15 = 75o75° West LongitudeWest75o W
10 A tougher example: 35oN, 120oW 2. It is 12 noon at the Prime Meridian. You are on a boat where it is 4:00 am. You look up at the sky and determine the altitude of Polaris to be 35°. What is your latitude and longitude?Latitude: ALtitude of Polaris = LAtitude of observer 35oNLongitude: 8 (time difference) x 15o = 120o W35° N; 120 ° W35oN, 120oW