These maps present two totally 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 discuss makes you wish to take a look at Greenland on a map, you may discover its dimension. Greenland is the world’s largest island, overlaying greater than 836,000 sq. miles.
However is Greenland actually as massive as it would seem on a map? Seems, it will depend on the map.
Although globes provide a fairly correct image of the world’s geography, issues get loads trickier if you attempt to depict a sphere on a two-dimensional floor. The styles and sizes of land plenty can get distorted, and distances and instructions danger turning into wonky. There are a lot of totally different forms of world maps, and each has its strengths and weaknesses.
One of the vital widespread map sorts known as the Mercator projection, named for the Sixteenth-century Flemish cartographer who invented it. That is the one you might have seen in an atlas as a child, and a model of it is utilized in on-line mapping instruments similar 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 dimension because the continent of Africa on a Mercator map, though Africa is about 14 occasions bigger.
“Mathematically [the parallels and meridians] get pulled aside, pulled in several 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 big,” 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 dimension. The Robinson projection, which tries to higher steadiness the configurations and dimensions of land plenty, sought to resolve the “Greenland downside.” And final 12 months, the African Union threw its assist 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 decide at a given time actually will depend on 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 deal with only a very slender subset is I feel one other downside that needs to be addressed.”
