GEOGRAPHY

Students throughout Boston are getting a radically different view of the world, one map projection at a time. (NPR)

Why is designing a world map so difficult? Use our activity to better understand what distortions occur when modeling a spherical surface on a flat map.

Teachers, scroll down for a quick list of key resources in our Teachers Toolkit.

Discussion Ideas

• Boston Public Schools are sending social studies teachers maps using the Gall-Peters projection, top, instead of the Mercator projection. What is a map projection?
  • A map projection is a depiction in which shapes on a globe are transferred to a flat surface. As the video above tells you “making a flat map of a round planet is a problem all cartographers have to deal with.”
    • All map projections contain distortions. When choosing a map projection, a cartographer must decide what spatial features he or she wants to prioritize, and deal with distortions surrounding other spatial properties. Spatial properties that are subject to distortion are:
      • shape
      • area or size
      • distance
      • direction
    • National Geographic uses the Winkel tripel map projection for its large-scale maps. The name tripel (German for “triple”) refers to Winkel’s goal of prioritizing three spatial properties: area, distance, and direction.

• What’s wrong with the Mercator projection? Cue the video to about 1:24 for some help.
  • Nothing is wrong with it; it was just designed for a different time and purpose.
    • Created by Gerardus Mercator in 1569, the projection was designed to help European adventurers navigate the globe. The projection prioritizes linear shape and scale. In particular, it preserves angles, a key factor for seafaring explorers. But the projection distorts the size of objects as latitude increases. Key distortions in the Mercator projection include:
      • Greenland appears massive, larger than Australia and Africa. In reality, Australia is three-and-a-half times larger than Greenland. Africa, the second largest continent on Earth, is fourteen times larger.
      • Alaska appears larger than Brazil. In reality, Brazil is five times larger.
      • Antarctica appears to be the largest continent, when only Europe and Australia are smaller.
  • Most web-based maps, including Google Maps and our own MapMaker Interactive, use a Mercator projection called Web Mercator. The projection is useful because users can easily zoom with little relative distortion.

• What spatial properties does the Gall-Peters projection prioritize?
  • The Gall-Peters projection prioritizes size. The area of different land masses is fairly proportionate, and the European “North” does not dominate the projection.
    • Despite these benefits, the Gall-Peters projection has its flaws. It doesn’t enlarge areas as much as the Mercator projection, but certain places appear stretched, horizontally near the poles and vertically near the Equator.

• Why do officials at Boston Public Schools think exposing their students to the Gall-Peters projection is important?
  • “Eighty-six percent of our students are students of color,” says Hayden Frederick-Clarke, Boston Public Schools’ director of cultural proficiency. “Maps that they are presented with generally classify the places that they’re from as small and insignificant. It only seems right that we would present them with an accurate view of themselves … Once students feel like the school isn’t being truthful, there’s a tendency to shut down and reject information.”
    • “This is the start of a three-year effort to decolonize the curriculum in our public schools,” said Colin Rose, assistant superintendent of opportunity and achievement gaps. “So this is about maps, but it isn’t about maps. It’s about a paradigm shift in our district. We’ve had a very fixed view that is very Eurocentric. How do we talk about other viewpoints? This is a great jump off point.”

• Do you have maps in your classroom? What projection do they use? What map do you think your school should use? Why?
  • Take a look at the images available in Wikimedia Commons for some ideas.
  • Take a look at the gorgeous AuthaGraph projection, which just won a design award last year. (It’s one of our favorites!)
  • Consider what information you want to convey, or what spatial properties you want to emphasize.
    • Are you helping explore uncharted areas of the Earth?
    • Do you want students to get a good idea of where their ancestors came from?
    • Do you want them to focus on the world ocean, as opposed to its continents? (Learn more about that decision here!)
  • Consider what your favorite map projection says about you.

TEACHERS TOOLKIT

NPR: Boston Students Get A Glimpse Of A Whole New World, With Different Maps

Business Insider: The Most Popular Map Of The World Is Highly Misleading

Nat Geo: Investigating Map Projections activity

Nat Geo: The Cartographer’s Dilemma video

Nat Geo: Selecting a Map Projection video study guide

Wikimedia Commons: Images of map projections