File talk:World relief map with isopachs of crustal thickness.jpg

Any map is pretty muck useless without a legend, so please add a legend to this picture. Confusingly the colors don't seem to have a link with the topic (thickness of continentel crust) but is probably just average altidude of solid surface? But then Antartica seems weird (most would be below sealevel without the ice). — Preceding unsigned comment added by Codiv (talk • contribs) 13:30, 4 May 2021 (UTC)

Correct and correct. The colors indicate elevation above sea level. It's the usual way to indicate this and a key for the colors is actually not that necessary. Green means lowlands, yellow means moderate elevation (low mountain ranges and uplands), brown means high elevation (high mountain ranges and uplands, in the polar regions the elevation obviously includes the continental ice shields), blue tones indicate elevation below sea level (the darker the deeper). It is sufficient to distinguish between continents and ocean basins, and, on the continents, between lowlands and high mountain ranges. That's it.

And yes, large parts of the rocky surface of the polar landmasses are below sea level due to the load of the ice shields. This is a phenomenon called isostasy. --Gretarsson (talk) 09:02, 25 May 2023 (UTC)