From BBC News: Megaflood ‘made Island Britain’:
Britain became separated from mainland Europe after a catastrophic flood some time before 200,000 years ago, a sonar study of the English Channel confirms.
The images reveal deep scars on the Channel bed that must have been cut by a sudden, massive discharge of water.
Scientists tell the journal Nature that the torrent probably came from a giant lake in what is now the North Sea.
Some event – perhaps an earthquake – caused the lake’s rim to breach at the Dover Strait, they believe.
Dr Sanjeev Gupta, from Imperial College London, and colleagues say the discharge would have been one of the most significant megafloods in recent Earth history, and provides an explanation for Britain’s island status.
“This event, or series of events, that caused [the breach] changed the course of Britain’s history,” Dr Gupta told BBC News.
“If this hadn’t happened, Britain would always have been a peninsula of Europe. There would have been no need for a Channel Tunnel and you could always have walked across from France into Britain, as early humans did prior to this event.”
I blame global cooling, or maybe global warming.
with no ozone, days get warmer and nights get colder. Global cooling exists because of global warming