Map Projections

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# Map Projections - PowerPoint PPT Presentation

## Map Projections

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##### Presentation Transcript

1. Map Projections

2. Students must be able to identify and understand the following projections. • Mercator • Polar • Robinson

3. Mercator Projection Most Accurate in the tropics from Cancer to Capricorn Most Distortion at the North and South Poles

4. Mercator Projection • Used for: • Locating Latitude and Longitude • Sea Captains use it for navigation at sea

5. Mercator Projection • Characteristics: • All lines are at 90 degree angles • Simplest to read • Accurate direction • Distorted size, distance, shape

6. Robinson Projection Most Accurate at the equator Most Distortion around the outer edges

7. Robinson Projection • Same characteristics as the Mercatorexcept: • lines of longitude are curved • shapes at the poles are flat and not as distorted • used mostly in classrooms--one of the most accurate maps

8. Polar Projection Most Accurate at the poles Most Distortion around the outer edges

9. Polar Projection Used for navigation of air planes

10. Polar Projection • Characteristics: • Distances and direction are accurate from the center along the longitude lines. • Size and shape are accurate at the center of the map

11. Types of Maps Conic Projections • A conic projection is a map made by projecting points and lines from a globe onto a cone. • The cone touches the globe at a particular line of latitude along which there is very little distortion in the areas or shapes of landmasses. • Distortion is evident near the top and bottom of the projection.

12. Types of Maps Gnomonic Projections • A gnomonic projection is a map made by projecting points and lines from a globe onto a piece of paper that touches the globe at a single point. • Gnomonic projections distort direction and distance between landmasses. • Gnomonic projections are useful in plotting long-distance trips by air or sea.

13. Types of Maps Gnomonic Projections • Great circles are imaginary lines that divide Earth into two equal halves. • On a sphere such as Earth, the shortest distance between two points lies along a great circle. • Navigators connect points on gnomonic projections to plot great-circle routes.