Labs / Geography
Map Projection Distortion
You cannot flatten a sphere without tearing or stretching it. Switch between Mercator, equal-area, and azimuthal projections and watch the same coastlines and grid of little circles deform. Each blue circle should be the same size on the ground — where it balloons or squashes, the map is lying about area or shape. Move your cursor over the map to read the local distortion.
area —shape ω —Grn —Afr —
What to try
- On Mercator, Greenland (2.2M km²) looks nearly as big as Africa (30.4M km²). How much does the “shown” area shrink when you switch to equal-area?
- Why do the Tissot circles stay perfectly round on Mercator but grow enormous near the poles, while equal-area keeps them the same size but squashes them into ellipses?
- Slide the standard parallel up to 45°. Where does the map now become true-to-scale, and which places pay for it with the most distortion?
- Switch to the azimuthal view. What happens to shapes and distances as you drag the cursor from the centre point out toward the rim?
- Can any single flat map show area, shape, and distance all correctly at once — or does fixing one always break another?