These maps present two totally different approaches to depicting Greenland. The left map is an orthographic projection, emulating a globe. The correct map is a Mercator projection, which exaggerates the sizes of landmasses — together with Greenland — which are closest to the poles.
Alyson Harm/NPR
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Alyson Harm/NPR
President Trump is once more floating the thought of annexing Greenland, the semiautonomous Arctic island that may be a territory of Denmark.
Greenland’s location between North America and Russia offers it strategic worth for the U.S., which already has a military base there. “We do want Greenland, completely,” Trump stated on Sunday. “We want it for protection.”
If all this discuss makes you need to take a look at Greenland on a map, you may discover its measurement. Greenland is the world’s largest island, protecting greater than 836,000 square miles.
However is Greenland actually as massive as it would seem on a map? Seems, it is dependent upon the map.
Although globes supply a reasonably correct image of the world’s geography, issues get rather a lot trickier whenever you attempt to depict a sphere on a two-dimensional floor. The sizes and shapes of land plenty can get distorted, and distances and instructions threat turning into wonky. There are lots of totally different types of world maps, and every one has its strengths and weaknesses.
One of the crucial widespread map varieties is known as the Mercator projection, named for the Sixteenth-century Flemish cartographer who invented it. That is the one you will have seen in an atlas as a child, and a version of it is utilized in on-line mapping instruments corresponding to Google Maps.
Mercator’s map takes the Earth’s latitudes and longitudes (parallels and meridians) — which curve across the spherical globe — and makes them straight traces.
This allowed sailors to plot a course between any two factors utilizing a straight line, however it additionally created distortions within the map the additional you bought from the equator. For instance, Greenland appears roughly the same size because the continent of Africa on a Mercator map, despite the fact that Africa is about 14 occasions bigger.
“Mathematically [the parallels and meridians] get pulled aside, pulled in numerous quantities and magnitudes from the equator in the direction of the poles, so you find yourself with this kind of exaggerated impact, if you’ll, within the higher latitudes the place landmasses look enormous,” stated Fritz Kessler, a Penn State geography professor and map projection skilled.
There have been organized efforts to maneuver away from the Mercator projection and use alternate options that supply a extra correct view of relative land measurement. The Robinson projection, which tries to higher stability the dimensions and shapes of land plenty, sought to resolve the “Greenland drawback.” And final yr, the African Union threw its support behind a push to interchange Mercator with the Equal Earth map, which higher renders the continent’s scale.
However which of the quite a few map projections you choose at a given time actually is dependent upon what you are utilizing the map for, based on Kessler.
“Is it going for use to measure distances or instructions? Angles? Areas? Present distributions of thematic information, , inhabitants?” he stated. “There’s a whole lot of projections that can be utilized, and the truth that we give attention to only a very slender subset is I feel one other drawback that ought to be addressed.”
