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These maps present two completely different approaches to depicting Greenland. The left map is an orthographic projection, emulating a globe. The precise map is a Mercator projection, which exaggerates the sizes of landmasses — together with Greenland — which might be closest to the poles.
Alyson Harm/NPR
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Alyson Harm/NPR
President Trump is once more floating the concept of annexing Greenland, the semiautonomous Arctic island that could 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 navy base there. “We do want Greenland, completely,” Trump stated on Sunday. “We want it for protection.”
If all this speak 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 sq. miles.
However is Greenland actually as giant as it would seem on a map? Seems, it is determined by the map.
Although globes provide a reasonably correct image of the world’s geography, issues get quite a bit trickier if you attempt to depict a sphere on a two-dimensional floor. The sizes and shapes of land lots can get distorted, and distances and instructions danger changing into wonky. There are numerous completely different kinds of world maps, and every one has its strengths and weaknesses.
One of the widespread map varieties is named the Mercator projection, named for the Sixteenth-century Flemish cartographer who invented it. That is the one you could have seen in an atlas as a child, and a model of it is utilized in on-line mapping instruments equivalent 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 strains.
This allowed sailors to plot a course between any two factors utilizing a straight line, but it surely additionally created distortions within the map the additional you bought from the equator. For instance, Greenland seems roughly the identical measurement because the continent of Africa on a Mercator map, despite the fact that Africa is about 14 instances 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 knowledgeable.
There have been organized efforts to maneuver away from the Mercator projection and use alternate options that provide a extra correct view of relative land measurement. The Robinson projection, which tries to raised stability the configurations and dimensions of land lots, sought to resolve the “Greenland downside.” And final 12 months, the African Union threw its assist behind a push to switch 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 determined by what you are utilizing the map for, in response to 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 believe one other downside that must be addressed.”
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