From a New Yorker article on sea-level rise called “The Siege of Miami,” by Elizabeth Kolbert, in the December 21 and 28, 2015, edition:
As the ice age ended and the planet warmed, the world’s coastlines assumed their present configuration. There’s a good deal of evidence—much of it now submerged—that this process did not take place slowly and steadily but, rather, in fits and starts. Beginning around 12,500 B.C., during an event known as meltwater pulse 1A, sea levels rose by roughly fifty feet in three or four centuries, a rate of more than a foot per decade. Meltwater pulse 1A, along with pulses 1B, 1C, and 1D, was, most probably, the result of ice-sheet collapse. One after another, the enormous glaciers disintegrated and dumped their contents into the oceans. It’s been speculated—though the evidence is sketchy—that a sudden flooding of the Black Sea toward the end of meltwater pulse 1C, around seventy-five hundred years ago, inspired the deluge story in Genesis.
Considering that there’s more than one flood story in ancient literature—as the SFE entry on the theme of disaster points out, “Tales of universal floods are at least as old as The Epic of Gilgamesh (circa 2000 BCE)”—it’s easy to believe that something actually occurred way back when, before the invention of writing, and also before history was separated from mythology. Because I encountered Gilgamesh long ago, in college, the idea of a real event doesn’t surprise me, but it’s fascinating that scientists are able to make a guess about when it happened.