During the last ice age, there was a stretch of land connecting Great Britain to continental Europe called 'Doggerland'. It gradually disappeared under the sea, but are there any known references to it in the folk memories of Northern Europe? I've heard that the Australian Aborigines have names for mountains that disappeared under the ocean thousands of years ago, but I've no idea if that's true.
This is an article concerning the recent Australian research. I know of no attempt to conduct similar work on Doggerland sites - but it's a great idea. I also know of no stories that might be used for this sort of research. Perhaps someone else will have some suggestions.