The Art and Science of Map Making: Distortions and Projections

🗺️Map projections are necessary to represent the spherical Earth on a flat surface, but they introduce distortions.

🌍The Mercator projection, commonly used for navigation, preserves shape but exaggerates the size of polar regions.

🌐The Gall-Peters projection produces an equal-area map, accurately representing size but distorting shape.

🌎With the advent of GPS, map projections have become more about aesthetics and design.

📍Cartographers have developed various non-rectangular projections to strike a balance between size and shape accuracy.

Why do map projections introduce distortions?

—Map projections are necessary because it is impossible to accurately represent a spherical Earth on a flat surface. Therefore, the process of projection inevitably introduces distortions in shape, size, direction, and land area.

What is the Mercator projection used for?

—The Mercator projection, popularized by Gerardus Mercator in the 16th century, is primarily used for navigation. It preserves shape and angles, making it useful for nautical charts and compass-based navigation.

What are the drawbacks of the Mercator projection?

—One of the drawbacks of the Mercator projection is the exaggeration of size, especially in polar regions. The distortion creates an inaccurate perception of the relative sizes of different landmasses.

Which projection accurately represents size?

—The Gall-Peters projection, also known as an equal-area map, accurately represents size by sacrificing the preservation of shape. It provides a more equitable view of land areas in comparison to the Mercator projection.

What factors influence the choice of map projection?

—The choice of map projection depends on the purpose of the map and the specific needs of the user. Factors such as aesthetics, design, preservation of size or shape, and accuracy of direction play a role in selecting a suitable projection.

00:04Map making requires cutting open the globe to create a flat map, introducing distortions.

01:10Different map projections, such as the cylindrical projection, are used to translate the globe onto a flat surface.

02:51The Mercator projection preserves shape and is useful for navigation, but it distorts size, making Greenland appear larger than Africa.

03:27The Gall-Peters projection accurately represents size but distorts shape.

04:19With the advent of GPS, map projections have become more about aesthetics and design.

05:23There is no one right map projection, and cartographers have created a wide variety of options to balance size and shape accuracy.