However, there are theories that some flood may have occurred long, long time ago. This would explain why we have stories about floods coming from different cultures that didn't have contact with each other prior to globalization.
A while ago, I tried to find details on all these various flood stories from different cultures. I came to the conclusion that the assertion that there are multiple flood myth stories is, itself, a myth. It seems some people have gone to great extent to dig up and list every ancient and medieval reference to a flood or deluge and try to use it as evidence.
Worse, most accounts only appear after a culture has had contact with Christianity and the biblical flood myth. To pick a ridiculous example, Lebor Gabála Érenn, (compiled in the middle ages in Christian Ireland, and repeats biblical accounts) is cited by some as evidence of another culture with an ancient flood myth.
Most accounts that resemble the Noah's ark story are Sumerian or Mesopotamian in origin. All of these accounts seem to stem from the Epic of Gilgamesh. The story of Utnapishtim in the Epic of Gilgamesh has so many similarities to the Noah's ark story, it has to be from the same source, or one is copied from the other. In both stories an extremely large rectangular boat is built (admittedly different dimensions) and is loaded with animals and Utnapishtim/Noah's family. The flood comes and the boat eventually comes to rest on a mountain. Both Utnapishtim and Noah release birds to find land in the process.
I think the story in the Epic of Gilgamesh is the source for the Noah's Ark story (not vica versa) because:
- The Epic of Gigamesh is much older than any written account of Noah's flood.
- The Epic of Gigamesh was a widely repeated story in the region and there is around 1000 years difference in age between the earliest and the last known written accounts.
- Early Israelites would have heard the stories of the Epic of Gilgamesh from one or more neighboring peoples.
- Isrealites captured in Babylon would have heard the stories of the Epic of Gilgamesh from their captors.
- The flood part of the Epic of Gilgamesh is part of a wider set of stories that make much more sense (as a work of fiction).
- The Epic of Gilgamesh doesn't purport to be in any way historical.
I should add that am no professional researcher or historian, and I would be interested in any other views.