2489: Bad Map Projection: The Greenland Special

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Bad Map Projection: The Greenland Special

Title text: The projection for those who think the Mercator projection gives people a distorted idea of how big Greenland is, but a very accurate idea of how big it SHOULD be.

Explanation

This explanation may be incomplete or incorrect: Created by a AFRICA SIZED NOT AFRICA SIZED ISLAND. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon. If you can address this issue, please edit the page! Thanks.

This is presumably a reference to how Greenland is extremely large in the Mercator projection, due to proximity to the North Pole.

Transcript

This transcript is incomplete. Please help editing it! Thanks.

Bad Map Projection #299:
The Greenland Special
Equal-area map preserves size everywhere except Greenland, which uses the Mercator projection.

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Discussion

I want this map, but s/Greenland/Alaska (because that is how big Alaska should be) Orion205 (talk) 05:38, 15 July 2021 (UTC)

What are you trying to say? Beanie ^talk 09:50, 15 July 2021 (UTC)

s/Greenland/Alaska is the syntax to swap Greenland and Alaska in programs such as SED. Orion205 want's "The Alaska Special" map projection. 172.69.42.50 21:32, 15 July 2021 (UTC)

Hi, User:Beanie, sorry I've been messing with your well-intentioned Transcript edits, with my own well-intentioned ones. I seem to have difficulty with the Edit Conflict page not being very helpful (on this wide but short small screen, and a browser that wants me to resubmit things and lose newer stuff if I even think of switching windows mid-edit), especially when it seems we're each pushing little changes in very short intervals (often takes longer to tap in the edit-Summary!), and I'm formally not changing that any more. Except that it's so descriptive, I absolutely wouldn't object to some other way of describing the 'Supertitle', like a Subtitle but above the in-comic main title-scrawl, for example. (I only 'reverted' that back over because it was easier than trying to snipe in all the other retweaks it looked at one point that I needed to reapply when I couldn't work out why it was submitting so 'wrong'.) You've probably safely and sanely un-nuked my 'nuke' by the time I've added this comment, of course, but I can't know for sure yet... ;) 141.101.99.177 10:24, 15 July 2021 (UTC)

Ah well, I'm trying to conform to the usual style of transcripts. I will compare this to other examples of 'Bad Map Projections', in hope of styling the transcript right :). Beanie ^talk 10:35, 15 July 2021 (UTC)

I would say that two of those others are contrary to the general Transcript format that people have been arguing about recently, and the third is much closer to how the other edit looked (albeit for a bottom-titled). Not my place to retro-edit en-mass, though. Just commentary. And do we put links in the Transcript, these days? If not in the main Explanation, maybe as Trivia? Whatever. 162.158.159.48 15:37, 15 July 2021 (UTC)

Projection

Does anyone know which projection the rest of the map is? Djbrasier (talk) 13:10, 15 July 2021 (UTC)

The non-Greenland map projection is very close to **Kavraiskiy 5** (not 7) except the South Pole is rounded like Mollweide. - Frankie (talk) 12:09, 15 July 2021 (UTC)

I have a strong suspicion that it's projection which doesn't map ANY part of globe to the area North Greenland occupies. -- Hkmaly (talk) 14:12, 16 July 2021 (UTC)

Uh, hullo. I just made that very same point (NPI!) as part of one of my edits. And if you overlay the Tobler map (in particular) it is clearly a very decent match to at least a very close relative in that elliptical family (with the poles being points on the edge-oval, not stretched out to lines and reinforcing the non-equal-areaness of the suggested Kavrayskiy types). Only one person knows for sure, though, and apparently Randall doesn't read here (or at least care to comment, SFAIK), so consider this just a bit of mapgeek speculation. 162.158.159.42 14:31, 16 July 2021 (UTC)

FWIW, Kavrayskiy 5 is an equal area map very similar to Tobler Hyperelliptical except at the poles. - Frankie (talk) 01:59, 17 July 2021 (UTC)

New xkcd up: Pre-Pandemic Ketchup 162.158.78.64 15:08, 16 July 2021 (UTC)

Ideally, we should overlay the xkcd map to Tobler (not K5, the poles - or at least the visible bits at the south - are clearly different in the same way K5 is to Tobler) in the same way. I'm sure the other day I saw an assertion it was K7 (clearly wrong, to my eyes) but not sure it was even here (edited out?) so let me just reinforce my objection to that without any obvious reason in case it gets read by the same people who share my other relevent lurking/participatory habits. 141.101.99.13 09:00, 19 July 2021 (UTC)

Before I totally forget, and long after I should probably have completed the job, for reference I created https://imgur.com/a/ZJ5aCSa (easier to put there than upload here, when I did it). It shows the close match between the Tobler map (ripped from Wiki, and rescaled to the line drawing without being reproportioned) except for probable drawing differences. The 'real' Iceland is actually under the Mercator Greenland (again, ripped from Wiki, needed slight rotation as well as rescaling) forcing the drawn one to be moved. Svalbard could not be matched despite other near-latitude features working well and there's some other minor coastal disagreements (greater or lesser area under the illustrated version). This is perhaps not the bestest-of-best-fits, to the pixel, but it is close. (I did not upload the x2 version of the image, but rescaled back down first. Intended to perfect things before any unveiling, with the ultimate possibility of fully animating transitions between the various display options as well, without making a super-huge .gif as a result.)

The Mollweide and various Kavrayskiy versions mismatched (or, if you prefer, are systematically unmatchable) notably more from the xkcd so, yes, it's very much a Tobleresque original, or some projection I didn't get my hands on to compare. And the remaining 'errors' are from the redrawing process itself.

Finally, I splined in some revised continuations of the Tobler latitude/longitude marks to try to be consistent with their actual passage over/round the Mercatorial Greenland bit. Which was tricky (east-westings winding up and through the gap between G and UK in particular) and might not be how others might have done it, but was a lot easier than trying to overlay the relevent Tissot markings. - So that's how it is, for anyone who is still following this. Enjoy? 162.158.155.157 20:55, 24 July 2021 (UTC)