''All we really see is some correlations in time,'' Dr. Ryan said in an interview. ''It doesn't necessarily mean there's a cause and effect. It may be only a coincidence, but it's too much of a coincidence not to be further investigated.''

Dr. Pittman said, ''It's something the archeologists are going to have to deal with one way or another.''

In the BBC program, Dr. John Dewey, a geologist at Oxford University, said: ''The geology is very clear. The real question is, does it explain the biblical flood or some other phenomenon.''

Dr. Stephanie Dalley, an authority on Gilgamesh at Oxford, said she doubted there was any connection between the Black Sea event and the mythological flood, noting the wide separation of the two in geography and time. The Gilgamesh who may have inspired the epic was possibly a ruler of the Sumerian city of Uruk around 2600 B.C., two-and-a-half millenniums after the Black Sea deluge, and the earliest known written versions of the heroic legend are on clay tablets from about a millennium after his rule.

Dr. Ryan and Dr. Pittman may be on firmer ground suggesting a link between the abrupt rise of the Black Sea and cultural changes in Europe and elsewhere. They point to the sea's pre-flood history in making their case.

Beginning 12,000 years ago, just as the world had recovered from the last ice age, Europe and parts of Asia underwent a 1,000-year interval of especially arid conditions. The level of the Black Sea plummeted, but still its fertile shore must have been an inviting oasis. People who already lived there or flocked there, responding to the environmental crisis all around, could have developed an early farming culture. No one is sure, of course, because any traces of their settlements are now under water.

Soon after the arid period ended, extensive farming appeared nearby in Anatolia, now part of Turkey, and northern Greece. The two geologists suggest that with an ample supply of fresh water at hand, the Black Sea people could have been successful farmers, too.