Map Projections & Types “Not only is it easy to lie with maps, it's essential. To portray meaningful relationships for a complex, three- dimensional world on a flat sheet of paper or video screen, a map must distort reality.” -Monmonier, M

3-D to 2-D Globe – 3-D representation of the Earth - Shows accurate size and distance -Scale is too big to show much detail Map – 2-D representation of the Earth’s surface - shows greater detail - because of Earth’s curves, causes distortion

Distortion Shape (the geographic shape of a feature) Area (the amount of area of a feature) Distance (how far away features are from each other) Direction (the orientation NESW traveling from one feature to another)

Great Circle Routes An example of how the Earth’s curvature affects distance and direction.

Kinds of Map Projections Planar Projection - Most accurate at it’s center, often used for Poles - Images get more distorted the further from the center they move

Cylindrical Projection Projection of the globe onto a cylinder Very accurate near Equator Shapes and distances distorted near poles

Conic Projections Best suited for showing limited east-west areas that are not too far from Equator Very accurate, with distances and directions

Common Map Projections Winkel Tripel Projection -Most common -Good balance between size and shape

Robinson Projection Minor distortion along edges and poles Good detail on shapes of continents

Goode’s Interrupted Equal Area True size and shape Distances greatly distorted

Mercator Projection Accurate direction and shape of land masses Greatly distortes sizes near poles

Questions Which type of projection most accurately shows the Poles? What are the positives and negatives of Goode’s Interrupted Equal Area Projection?