"[Atlantis] once had an extent greater than that of Libya and Asia (Turkey); and, when afterward sunk by an earthquake, became an impassable barrier of mud to voyagers sailing from hence to the ocean." Plato c.428 - c.347 BC
https://ascendingpassage.com/plato-atlantis-timaeus.htm

To the the south of Iceland and west of Portugal is a three way tectonic plate boundary that has a large underwater landmass. If this landmass is the remains of a continent that plunged ~1km down in a single day, then that would make a great turgid mess in the north atlantic. The entire ocean current system would be wildly reset. This would deposite giant mud barriers were strong sediment heavy flows slowed down and dropped their sediment. The surface waves would cause a train of mud tsunamis. The entire planet's weather is altered suddenly from the ocean currents being sorting itself out.

All I'm saying is maybe the "New World" for the Europeans in ~1500s was really actually new because the mud barrier finally cleared out?