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Map Projections

Map Projections. Map Projections Putting a sphere on a flat surface messes up certain realities: Distance Direction Shape Area Each map keeps one or two things true (pros), but the others are not accurate (cons). Mercator Pros : Direction Cons : Shape Distance Area

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Map Projections

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  1. Map Projections

  2. Map Projections Putting a sphere on a flat surface messes up certain realities: • Distance • Direction • Shape • Area Each map keeps one or two things true (pros), but the others are not accurate (cons).

  3. Mercator Pros: Direction Cons: Shape Distance Area Africa is actually 14 times larger than Greenland!

  4. Robinson Pros: Cons: Better area Directionand shape Distance

  5. Goode homolosine Pros: Shape Area Cons: Direction Distance

  6. Latitude and Longitude

  7. Hemispheres

  8. Hemispheres

  9. The Earth’s Grid Any spot on Earth can be plotted with latitude and longitude. • Lines of latitude run east-west • “Lateral” means “side-to-side” (lateral pass) • Also called parallels • Measured in degrees of N or S • 0° latitude is the Equator • 90° N is the North Pole • 90° S is the South Pole

  10. Latitude Measure North Equator Measure South

  11. Upper Latitudes Lower Latitudes

  12. Longitude Lines of longitude run north-south “All lines of longitude are long” Also called meridians Measured in degrees of E or W 0° longitude is the Prime Meridian Runs through Greenwich, England, just outside London 180° E/W is the International Date Line

  13. Longitude 180° W 180° E 0° Prime Meridian Measure West Measure East

  14. 35º N 34º 5’ N 34º N 18º E 19º E 18º 25’ E

  15. The Earth’s Grid A specific location uses N or S and W or E for each coordinate pair Three ways to show coordinates: Degrees, minutes, seconds: 30°, 15’, 45” N; 54°, 20’, 10” W 1 degree = 60 minutes; 1 minute = 60 seconds **Note: This is not in reference to time! Deg:min:sec : 30:15:45N, 54:20:10W

  16. Three ways to show coordinates continued: 30:15:45N, 54:20:10W = • Decimals: 30.2625, -54. 336111 ** (south and west are negative numbers) • Found by dividing minutes/60 • i.e. 15 minutes = 15/60 = .25 • And then seconds/3600 • i.e. 45 seconds = 45/3600 = .0125 • Add the two together: • .25 + .0125 = .2625

  17. Latitude and Longitude Together, any point on Earth can be plotted on a map Use both coordinates together: Latitude, longitude 40° N, 85° E 10° S, 15° W Walton:33:59:20.663 N, 84:26:30.718 W This is the Front Office

  18. Why Degrees, Minutes, Seconds? • A circle is 360° • When computing various angles, we base our measurements on degrees. • i.e. Right angles are 90 ° • An angle between 90° and 91° require requires minutes and seconds to find the specific angle. • In 3D, we add the Z Axis, • which requires the second degree measurement

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