A flood of biblical proportions cut the British Isles off from mainland Europe sometime between 450,000 and 200,000 years ago, according to a new study.
The research, based on three-dimensional sonar mapping of the English Channel, provides the strongest evidence yet that a catastrophic megaflood broke a land bridge that once connected what is now Britain and France.
"It is probably one of the largest floods ever identified," said Phillip Gibbard, a geographer at the University of Cambridge who wasn't involved in the study.
At its peak, the flood would have discharged water at a rate of about 264 million gallons (a million cubic meters) a second, gushing at speeds of up to 62 miles (100 kilometers) an hour, the researchers say. This is roughly equivalent to ten times the combined flow rate of all the rivers in the world.
...
The flood also marooned many animals and plants, so those species gradually evolved into different forms than their mainland cousins.
And humans appear to have avoided the newly made island altogether, leaving it unoccupied for over a hundred thousand years.
...
The great flood could help explain why Britain remained an uninhabited region for a large chunk of the archaeological record.
"There seems to be a large gap in the evidence for human occupation [of Britain] during cold and warm phases from about 180,000 until about 60,000 years ago," said Nicholas Ashton, an archaeologist at the British Museum in London.
...
"It wasn't until 60,000 years ago," Ashton said, "that humans—late Neanderthals—had the technological capabilities, such as more effective clothing and shelter, to survive the cold conditions."