The definition of "island" is a piece of subcontinental land completely surrounded by a body (or perhaps bodies) of water. In most cases we don't count rivers and canals as the surrounding bodies,[actual citation needed] although small pieces of land like Manhattan are exceptions, as is any bit of land entirely surrounded by the same watercourse, that splits around it. Inland islands surrounded by rivers can be called a "holm".
Randall's map's "Dubious Islands" are indeed not to be trusted — they leave out many less prominent rivers and canals which would break the map into many more additional "islands". For example, southern Nova Scotia, southern New Jersey, and the nearly 60-mile-long "Grand Strand" of South Carolina are also islands by the sense used here in recognizing the Cape Cod Canal as creating an island. These and many other omissions would be errors — except that Randall clearly labelled his islands "Dubious" (not to be trusted) from the start, and he is presumably well-aware of this map's stretching of reality.
The title text suggests that the map could be improved by digging a canal through the Traverse Gap, thereby splitting the large red "island" into two smaller "islands" with more pleasing shapes. Randall proposes to run for office in Minnesota (where the Traverse Gap is located) on the platform of digging this canal. This is unnecessary and would create little benefit to residents,[actual citation needed] but constituents who like interesting maps might vote for him.
These islands are possibly Randall's humorous interpretation of what drastic erosion (perhaps caused by continued climate-change inducing increased water movement. Sea level rise might also provoke some of these disconnections, but as some of the connecting waterways exist at over 7000 feet (over 2km) in elevation, this would require a worldwide rise in sea-level (and/or localised fall of land) that would cause other changes to the map of North America.
As a native of the North Country of Northern New York, I'm really disappointed that Randall didn't label the St. Lawrence river. :-( 22.214.171.124 22:49, 6 October 2023 (UTC)
Had a go at the Transcript. Plenty of problems with it, but I was attempting to be partway methodical (generally heading north-to-south, seemed easier than "north-and clockwise" or any other sweep, once I started to do it) and not actually mention 'quoted' words more than once. Unless they're actually written multiple times. (looking at you, Mississippi!)
But had no option but to repeat some of the quoted text within the label-descriptor 'tags', perhaps each actual fragment should indeed by given all boundaries, but I think that's better left for the table that will inevitably have to be put into the main Explanation. There one can actually list the named and unnamed bordering waters (river, canal, lake, sea and ocean) for actual reference.
Also the wording. Tried not to repeat "bounded by" synonyms too much, but maybe I should just have chosen one option and repeated it anyway, given the difficulties and contextual issues of doing it absolutely unrepeatably. But it's my best try (at just gone midnight, indicating how personally familiar I might be with the continental US's geography, or not). And thus over to you people who actually know more about the Mississippi than merely how to spell it. (Not sure I've read, and thus spelt, some of the other names given right, either. Definitely check and edit as necessary.) Perhaps a geographic map could (e.g.) even identify the "Nunavuk+" territory with a better actually known descriptor, too! Canada is even less my forté than the US. 126.96.36.199 23:50, 6 October 2023 (UTC)
Im shocked that Randall conflated the hudson and Champlain when the two dont connect, missing each other by a slim margin.
Source: i live close to lake george, the missing point 188.8.131.52 00:52, 7 October 2023 (UTC)
- The Champlain Canal crosses that gap. 184.108.40.206 06:13, 7 October 2023 (UTC)
Southern NJ is made an island by the Delaware River, the Delaware and Raritan canal and the Raritan river. -- 220.127.116.11 (talk) 03:06, 7 October 2023 (UTC) (please sign your comments with ~~~~)
I'm disappointed that Randall did not include the Rideau Canal in Ontario, Canada. It connects Ottawa, on the Ottawa River, that flows into the St. Lawrence River, with Kingston, on Lake Ontario, which also flows into the St. Lawrence River. 18.104.22.168 (talk) 05:22, 15 October 2023 (please sign your comments with ~~~~)
I came to this comic hoping to learn the names of the islands, and then to the explanation hoping they were present but hidden in some way. Irrational! JohnHawkinson (talk) 07:43, 7 October 2023 (UTC)
- There are no names because the islands shown are not normally considered islands, so have not been given "island names". Of course, you could name them based on typical geographical labels, like "Eastern United States", "South Florida", etc. Some of the regions are distinct enough to have names, such as Cape Cod Canal naturally creating the "island" of Cape Cod - although depending on your opinion, some parts of Bourne might be considered on the Cape but on the mainland side of the Canal.- jerodast (talk) 20:53, 8 October 2023 (UTC)
- Yes, the point was I anticipated being entertained by Randall's conception of the dubious names for the dubious islands. JohnHawkinson (talk) 00:12, 9 October 2023 (UTC)
It should be noted that the headwaters for the Mississippi are roughly 100 miles north and east of the beginning of the Red River of the North. It's not important, really, but it is quite a long stretch to dig if someone were to actually cross the Traverse Gap. 22.214.171.124 23:58, 7 October 2023 (UTC)
- Yes, strictly speaking, the Traverse Gap separates the headwaters of the Red River of the North (Lake Traverse) from the headwaters of the Minnesota River (Big Stone Lake), not Mississippi, but the Minnesota eventually flows into the Mississippi. The Gap itself is officially 1 mile long, but an easier connection method might be to dig a trench 1/2 mile due west to the Little Minnesota River (mostly in South Dakota) and let physics do the rest.126.96.36.199 15:12, 11 October 2023 (UTC)
There's also the Height of Land Portage, a 400m long strip of land along the US-Can border that separates the Great Lakes watershed from the Hudson Bay watershed. By contrast, the Traverse gap is ~1600m in length at its narrowest. 188.8.131.52 13:00, 9 October 2023 (UTC)
- Where is Long Island?
Oh! Wait. The map only shows _dubious_ islands. 184.108.40.206 (talk) 06:28, 7 October 2023 (please sign your comments with ~~~~)
- All actual islands (Hawaii, the myriad of ones in the Canadian arctic, etc) are not there, so I take it as read that this is the contiguous mainland continental North America (stopping at the Panama cut) with divided by all cross-waterways of any significance. i.e. major rivers, hence why no lichen-like tributary 'fan' incursions into these areas; major canals, which means massive irrigation projects (and any actual ship-navigable ones, I presume) or else ever ditch or drain would count, lakes of course (but there's a lot of lakes in the Canadian north that are not shown, let alone used as might be hydrodynamically linked).
- Compared with what Great Britain might look like, so subdivided, it looks positively restrained. I mean, you can probably remove all those with dead-ends to make the 'disconnection map' simpler. And, in today's age, all stretches that are no longer viable/continuous/navigable for various reasons like railways and major roads being slapped over/next to them and rendering them obsolete/uncared-for/etc, but that still leaves quite a lot of islands, such the cut(s, several!) between Thames and Severn, the Humber to various Lancashire 'outlets', etc. And that link doesn't even show the Caledonian Canal cross (alongside/within the Great Glen), the more southerly Forth And Clyde route, etc. 220.127.116.11 16:08, 7 October 2023 (UTC)
No mention of Two Oceans Creek? 18.104.22.168 (talk) 17:52, 7 October 2023 (please sign your comments with ~~~~)
- Um... yes? There's a link to Parting Of The Ways (I made a grammatical/contextual edit, to make more sense, but might need another tweak) which involves the Atlantic Creek/Pacific Creek split from North Two Ocean Creek, or so I just read myself. 22.214.171.124 18:37, 7 October 2023 (UTC)
At least in the case of the Panama Canal, it's not really a "body of water" at all. It's a series of water locks which allow humans to convey boats over what would otherwise be dry land. Yes, the boats are floating in water the whole time, but it's not like an artificial river was dug between the Atlantic and Pacific Oceans that a boat can just cruise on through. It takes a long time and the coordination of many people to get a boat through the canal. Oversimplified diagram here. --MeZimm 126.96.36.199 14:43, 9 October 2023 (UTC)
- Generally, though, there is some volume of water flowing through/past lock gates even when they're closed, via sluices, overspills, etc. No, you couldn't float a boat through them, but that doesn't mean there isn't a continuous watercourse. 188.8.131.52 16:23, 9 October 2023 (UTC)
If we're going for seriously dubious, I nominate the Colorado River, which flows from Baja California, up and over the Rocky Mountains, and down through Austin, Texas into the Gulf of Mexico. At least, that's what the substitute teacher made us draw on our homework maps in class in high school. She had some... problems. But it would've made an awesome river. Is there a special class of "island" where the rivers are connected by name? Mrkxcd (talk) 06:03, 26 October 2023 (UTC)
It is overgrown to the point of being unreadable, but there is a sign outside Olympia, WA that describes the "Olympic Island" the small island west of Washington/British Columbia. 
Contrast with general/typical patterns of river flow?
Would it be overstuffing the explanation to get into the basic logic of how water flows, which in its most simplified form wouldn't create islands - a small stream of water would only follow the most direct path to lower elevation. Thus, rivers tend not to "branch out" going downstream, only as you travel upstream, which is really the convergence of incoming water flowing downstream. As a result, they only partially divide up land on a continent, since you can just keep going uphill until you can get around the division.
Obviously, in real terrain, the volume of a river or lake causes it to spread out, so it CAN split into two different outflow channels. Then, we also build canals, further creating divisions.
It just struck me that the map here is almost a commentary on those water channels that don't follow the "basic" rule of simply going downhill.- jerodast (talk) 04:46, 9 October 2023 (UTC)
- I'm pretty sure all those bits of water do flow downhill (or, at a push, flow along a completely level bed by dint of more water being dumped in at one end whilst the excess is allowed to exit at the other). Just that it's not all the same direction along any particular composite route, with possibly multiple drain/source points wherever directions meet/diverge. And possibly you have to abstract out any lock-gates/similar as continuity even when closed.
- That some of the canals are sent through undulating topography (to be valid here, surely can't involve tunnels/aqueducts; but deep cuttings are a thing... as are channels atop embankments, making only slightly confusing in this regard if they designed wet or dry culverts under them to maintain the old cross-directional terrain profile) doesn't change the level/downwards gradients in their very local geography.
- The exact details are (deliberately?) lost in this topological-but-not-topographical diagram, however. ;) 184.108.40.206 13:17, 9 October 2023 (UTC)
Possible inspiration for this comic?
I just found this video https://www.youtube.com/watch?v=mN2flAvdQXU, dated September 21, 2023, which is about North Two Ocean Creek, and at 3:53 it describes the section of North America north and east of the Columbia River-Snake River-Pacific Creek-North Two Ocean Creek-Atlantic Creek-Yellowstone River-Missouri River-Mississippi River as an island. Mathmannix (talk) 13:49, 11 October 2023 (UTC)
Was this reddit thread created before the comic was posted? https://www.reddit.com/r/geography/comments/170xg7l/is_new_england_eastern_new_york_state_southern/ 220.127.116.11 01:48, 12 October 2023 (UTC)
- Ooh. Seems that way! Thu, October 5, 7:51 pm ET. The night before the comic was posted. - jerodast (talk) 09:40, 20 October 2023 (UTC)