No doubt Tolkien was influenced by such tales. I recall reading that he'd stated that "Middle-Earth is Europe". Similarly, the entire Hyborian Age in which Robert E. Howard's Conan the Barbarian operated was set in a pre-Europe, which had come into being after two cataclysms, one which destroyed Atlantis and another which further altered the landscape.
Indeed, he had a recurring dream (which I have had myself, incidentally, recurring) of watching a great towering wave, as high as the sky, rush in from the sea to sunder the land.
When I saw the movie Deep Impact, with the great towering wave come in, it reminded me of that dream. Turns out Tolkien had the same dream.
I am reminded of the recent Tsunami, that all of the natives on some island were saved because, from an oral legend passed on since time out of mind, when they saw the sea depart, they headed for the hills. Nobody alive, or in living memory, had ever seen a tsunami, but the ancient memory, the legend, the myth, left a concrete lesson.
So, when the sea departed, they fled.
And while civilization on all of the surrounding islands was being drowned,. they all lived.
I note that in the tsunami, too, that none of the herds of large animals perished. They, too, all fled to the hills for some reason.
It is instinctive in the species, it is written in the genes (how else could Tolkien and I, separated by 60 years of existence and unrelated, have had the same recurring dream?), it is somewhere embedded in the collective memory of the living things of the Earth, man and beast, of a terrible, catastrophic flood.
The Algonquian Indians too have their memory of it, doubtless when the glaciers melted and the seas surged and broke open the end of Long Island Sound, which used to be a lake. Why did this formerly seaside people, with legends of the Atlantic coast, flee one thousand miles inland, to live by the shores of the Inland Sea (the Great Lakes)?
Their legends say because of a disastrous flood.
The flood happened.
Probably in many different places in many different times, as the glacial walls broke and the seas rose suddenly, or the canyons were dug, or any number of things