Relative Size of Continents to Scale: Mercator vs. Peters Projection Map

After exploring the relative sizes of the planets in our solar system last week, we explored another key geographical misconception. The current map of the seven continents on planet Earth was created by an Euro-centric Flemish cartographer named Gerardus Mercator in 1569. Europe is exaggerated by a factor of more than two and is at the center of the map and Africa is dwarfed from its massive land area.

A few major misconceptions based on this map are:

• Alaska is nearly as large as the continental U.S.

• Greenland is roughly the same size as Africa.

• Europe (excluding Russia) is only a bit larger than South America.

• Antarctica dwarfs all the continents. 

In reality: 

• Alaska can fit inside the continental U.S. about three times. 

• Greenland can fit inside Africa about 14 times.

• South America nearly doubles Europe's land mass. 

• Antarctica looks like the second-smallest continent.

The surprising fact is that we have known of this misconception since at least 1800 after a man named Gall and later in 1974, a man named Peters created what is known as the Gall-Peters Projection Map. Yet, schools, textbooks, and atlases continue to preach the Mercator Projection Map to this day. Gall-Peters shows the actual flattened land mass.

Of the 56.8 million square miles of land on Earth, the continents make up the following percentages of Earth's land:

Greenland is about 1% but is not a continent; it is an autonomous country under Danish rule.

I had the students create a model of the continents in actual relative size (to scale} from Play-doh. This week, we had to separate the dough into fractions of fifths, tenths, and twentieths. I challenged them to cut off certain percentages of the whole. For example, when it came time to create South America, I had them separate the remaining dough into twenty equal parts and cut off 35%. For the younger group, I explained that 1/20th was equivalent to 5%. They all quickly realized that 7/20ths was equivalent to 35%. We did the same with Antarctica with the next remaining piece by cutting off 45% or 9/20ths.

I also encouraged them to create their own relative sized continents and to form the dough into a sculpture the shape of the Peters continents. The pdf below, has the Mercator Projection Map, Gall-Peters Map, and a third map of one laid on top of the other, the directions to cut up the play-doh, and the ratios based on 88,000 parts.

Of course, for the more ambitious students, I challenged them to figure out the fractions of each continent of the whole land mass using the ratios below. In addition, there are 21 pairs of ratios that they could simplify. For example, 

There are a total of 88,000 parts that make up the seven continents.

Below is a ratio of the parts of each continent of the total 88,000 parts. 

1. Try to simplify the fractions for each continent of the whole land mass of Earth.

2. Then, try to find each ratio between each pair of continents.