Old maps indicate Greenland was ice-free just 500 years ago

[JGeropoulas]

When you look at Greenland on Google Maps, it's completely flat - just white. No mountains, no terrain, nothing. But old maps from the 1500s and 1600s show something completely different.In this video, we're looking at historical maps that show Greenland with green land, channels, even trees. Maps from Mercator in 1570, Coronelli in 1592, and several others all show detailed terrain that doesn't exist on any modern mapping service. Scientists say the ice there is over a million years old, but these maps suggest otherwise.We'll also explore the mystery of an east-west canal that appears on multiple historical maps, the strange expedition route of Fridtjof Nansen in 1888, and what might be revealed as Greenland's ice continues to melt at record rates.

 

[axj]

Just saw the same video and it basically boils down to the question what those medieval maps were based on.

The channel through Greenland was likely based on an old Norwegian chronicle that Mercator and other cartographers mentioned as a source. Though the chronicle does not really talk about a channel crossing Greenland:

The Key Source: The "Historia Norwegiæ" (History of Norway)​

While not a saga in the traditional literary sense, this Latin chronicle (c. 1200-1300 AD) provides the most direct reference to a possible "channel." It states:

"Moreover, Greenland’s western region is traversed by a channel which is called ad montes ['to the mountains' or possibly a place-name]. It runs north under the icecaps (sub glacie)."

This is the closest any medieval Norse source comes to describing a channel cutting through Greenland.

It might have been a subglacial meltwater river exit they saw during the Medieval warm period.