Winkel Tripel Projection: National Geographic's Map of Choice

The Winkel Tripel projection is a modified azimuthal map projection created by German cartographer Oswald Winkel in 1921. Its name comes from the German word "tripel" meaning triple, referring to its goal of minimizing three kinds of distortion: area, direction, and distance.

Introduction

Since 1998, the Winkel Tripel has been the standard projection used by the National Geographic Society for its world maps. Studies have shown that it achieves the lowest mean distortion of area, distance, and direction of any standard map projection, making it arguably the best general-purpose world map.

How It Works

• Created: 1921 by Oswald Winkel
• Type: Modified azimuthal, compromise
• Method: Average of two projections

The Winkel Tripel is calculated by averaging the coordinates from two other projections: the Aitoff projection (an azimuthal equal-area variant) and the equirectangular (plate carree) projection. This averaging technique produces a map that inherits the best qualities of both parent projections.

The result is a map with curved parallels and meridians that converge gently toward the poles. The overall shape is an oval similar to the Robinson but with slightly different curvature that gives the polar regions a more natural appearance.

Distortion Characteristics

• Area Error: Lower than Robinson at poles
• Shape Error: Well-preserved at mid-latitudes
• Distance Error: Minimal along the equator and central meridian

The Winkel Tripel achieves remarkably low overall distortion. A 2007 study by Goldberg and Gott at Princeton compared projections using the Kavrayskiy distortion measure and found the Winkel Tripel to have the lowest combined area and shape distortion of any standard whole-world projection.

While no flat map can eliminate all distortion, the Winkel Tripel distributes it more evenly than most alternatives. The worst distortions occur at the corners of the map, which represent the polar edges, but even there they remain moderate compared to cylindrical projections.

National Geographic Adoption

• Adopted: 1998, replacing Robinson
• Reason: Lower overall distortion scores
• Influence: Seen by hundreds of millions

National Geographic selected the Winkel Tripel in 1998 after evaluating numerous projections for visual appeal and mathematical distortion properties. The society found that the Winkel Tripel offered slightly better area accuracy at high latitudes than the Robinson while maintaining comparable shape and distance accuracy.

As the projection used by National Geographic, the Winkel Tripel has become one of the most widely viewed map projections in the world. It appears in National Geographic magazines, atlases, wall maps, and educational materials distributed globally.

Comparison with Alternatives

• vs Mercator: Far less area distortion
• vs Robinson: Slightly better overall scores
• vs Mollweide: Better shape preservation

Compared to the Mercator, the Winkel Tripel dramatically reduces size distortion. Greenland on a Winkel Tripel map appears much closer to its true relative size compared to Africa. However, the Winkel Tripel is not equal-area, so precise area comparisons should still use a dedicated equal-area projection.

The difference between the Winkel Tripel and the Robinson is subtle and mostly visible in the polar regions. The Winkel Tripel tends to show Antarctica with slightly less area distortion and keeps the overall shape of continents marginally more accurate, particularly at high latitudes.

Practical Applications

• Reference Maps: Best general-purpose world map
• Thematic Maps: Widely used for global data
• Education: Increasingly used in classrooms

The Winkel Tripel excels as a general reference map where viewers need to get an overall sense of the world without severe distortion. It is particularly well-suited for maps showing global phenomena like climate patterns, political boundaries, or trade routes where neither pure area nor pure shape accuracy is required.

Educational publishers have increasingly adopted the Winkel Tripel for world maps in textbooks and atlases, following National Geographic's lead. Its balanced distortion makes it an excellent teaching tool for helping students understand the relative positions and sizes of countries.

Key Facts

• The Winkel Tripel was created in 1921 by Oswald Winkel as a triple-compromise projection.
• National Geographic adopted it in 1998, replacing the Robinson projection.
• It is calculated by averaging coordinates from the Aitoff and equirectangular projections.
• A 2007 Princeton study found it has the lowest overall distortion of any standard world map projection.
• The name "Tripel" refers to minimizing three types of distortion: area, direction, and distance.

Fun Facts

• Oswald Winkel was a German cartographer whose projection was largely forgotten until National Geographic revived interest in it.
• The Winkel Tripel was virtually unknown to the general public before National Geographic adopted it in 1998.
• The projection is one of the few maps created by averaging two other projections together.
• Winkel Tripel is sometimes misspelled "Winkel Triple" in English, though "Tripel" is the correct German spelling.

Final Thoughts

The Winkel Tripel projection represents the best available balance of competing cartographic demands. By minimizing the triple distortion of area, direction, and distance, it provides the most honest flat representation of our spherical planet. National Geographic's endorsement has made it the de facto standard for world maps in the 21st century.