Why is Greenland Considered an Island and Not Eurasia?

Cecil's Columns/Staff Reports
1

Possibly contrary to the [rather flippant] answer given, geologically, continents are more loosely categorized as “continents” based on things like crust thickness and age. The most obvious categorizer is size and tradition, but this is followed by susceptibility to subduction (the act of being forced under another plate and into the mantle). Islands are more easily subducted than whole continents, especially islands formed entirely due to volcanic (hot spot) activity, because most islands don’t have the deep lithospheric “roots” that the major continents possess.

Obviously, this isn’t true in every case, but is a much more scientific and measurable way of categorizing continents and islands.

2

Actually, there is no convenient definition for “continent”, although some revisionist geologists would like to create one to deal with, for example, Australia in a way that makes some sense of New Guinea and the surrounding islands.

The best way to deal with the situation would be to accept that the word “continent” is not a precise term, but a historical one, and that large islands aren’t really a part of any continent, except in a political sense, where needed (Iceland as part of Europe, for example, or Madagascar as part of Africa). After all, what continent can really claim the Hawaiian Islands, for example?

3

Due to it’s high latitude, the land area of Greenland appears quite exagerated on Mercator projection maps. A globe shows it in realistic terms.

4

There is no scientific way to distinguish a continent and an island. Any attempt to do so is likely to end in tears.

Continents are big, islands are small. Anything else is a post-hoc rationalization. Any attempt to categorize by crust thickness or age or suchlike and we have to explain why Madagascar and New Zealand aren’t continents.

5

Most continents have two mountain ranges, usually near two opposite coasts, with a craton, a relatively flat area stable over geologic time and generally including a shield, which is a section of land area with very old rocks, more or less stable since Pre-Cambrian times, usually sandwiched between the ranges. (This broad-brush sketch does not include internal lakes, localized massifs, peninsulas, coastal plains, and other appurtenances, just a very rough skeletal outline of the minima shared by continents.) In some ways the definition is pushing things a bit (e.g., the Brazilian highlands as the eastern range for South America), but it works. Except for Greenland, if an island has serious mountains, they comprise its central spine.

New Guinea, Borneo, and Madagascar, in that order, are the second, third, and fourth largest islands. They are respectively 785,753 km², 748,168 km², and 587,713 km². Australia, by contrast, is a whopping 7.6 million km². The difference is a full order of magnitude – Australia is nearly ten times the size of New Guinea, and well over ten times the size of any smaller island, from Borneo on down.

Greenland is the kicker: it has a low area (covered by ice, to be sure) between two uplands (also covered by ice for the most part), and its area is 2,130,800 km² – about 28% that of Australia, and a full 2.7 times that of New Guinea. It’s almost as if it were thumbing its nose at human efforts to draw lines to define two distinct ideas instead of regarding them as parts of a continuum.

6

Any possibility of singling Greenland out in terms of participation in Rodina and Pangaea?

7

Well, Greenland used to play drums for Pangaea, but there was this falling out. Greenland was doing a lot of coke and got extremely paranoid, ruined the hotel room, and tried to jump out the window. There was an ugly press conference where Pangaea kicked Greenland out and picked up Anatolia instead, which everybody said was a bad move even though Anatolia had ten times the range. Later, Greenland got out of rehab and hooked up with Rodina, but most people agree that it was never Greenland’s best work.

8

Greenland is geomorphologically part of North America – on the same plate, just divided at sea level by Baffin Bay and the connecting straits – much like Tasmania and New Guinea are parts of Australia separated by relatively shallow water bodies.

9

It’s all a matter of viewpoint. Remember that headline from A Victorian British newspaper - “Fog in Channel, Continent Isolated”.

Maybe we need three words: One for the largest contiguous landmass on a given continental shelf, one for any smaller landmasses separated by sea that share these continental shelves, and one for the microcontinents or volcanic islands that just jut straight up from the ocean bed.