You gotta remember that in those very ancient times of the flood myths (other cultures and religions in the region have flood myths) The “world” wasn’t the entire planet as we know it now. What they meant was their known world, or the Mediterranean and North African coast.
So it’s very likely that a massive flood maybe caused by an ice age thaw, caused the Mediterranean and ancient coastlines, where humans settled, to flood and destroy all their homes.
I don’t think so, but you can never say it’s isn’t possible that some guy built a barge and put his family, livestock, etc. On it and they survived the floods and thought they were the only ones
I’ve seen pretty strong evidence that the Mediterranean Sea used to not be a sea, and that the flood was the land bridge holding back the ocean failing and allowing the sea to form
While there are instances of catastrophic floods in the planet’s history, including some that overlap with human existence, I don’t think the story even needs to be based on one of those. Flooding in some areas is pretty common, like the Nile and its yearly flood cycle. People would have been very aware how sudden and dangerous they could be and it wouldn’t have been hard to imagine a flood that just kept rising instead of rising for a bit and then retreating.
The Bible flood mentions it raining for 40 days and nights, which wouldn’t have been a part of a flood caused by a barrier breach. I don’t know if it’s even possible for Earth to support a weather pattern that resulted in 40 straight days of raining at a rate that would cause flooding, so my guess is that the whole story is made up, imagining a flood event taken to extreme levels and using a mechanism that might have seemed reasonable at the time to “explain” it.
And, as more examples of something similar, modern culture includes a smorgasbord of ideas about how civilization can end, some based on historic cases of fallen civilizations, but most based on imagination or extrapolating what’s possible based on what we know.
