Massive megaflood thousands of years ago separated Britain from mainland Europe

A huge flood separated Britain from mainland Europe thousands of years ago, according to a new study by an Indian origin sedimentologist from Imperial College, London.

Washington, July 19 : A huge flood separated Britain from mainland Europe thousands of years ago, according to a new study by an Indian origin sedimentologist from Imperial College, London.

The team of Dr. Sanjeev Gupta and Jenny Collier found spectacular images of a huge valley tens of kilometres wide and up to 50 metres deep carved into chalk bedrock on the floor of the English Channel.

According to the duo, the deep scour marks and landforms, as revealed by the images, were created by torrents of water rushing over the exposed channel basin.

"To the north of the channel basin was a lake, which formed in the area now known as the southern North Sea. It was fed by the Rhine and Thames, and impounded to the north by glaciers and dammed to the south by the Weald-Artois chalk ridge, which spanned the Dover Straits," the researchers said in their study in the journal Nature.

According to the duo, a rise in the lake level eventually led to a breach in the Weald-Artois ridge, carving a massive valley along the English Channel, which was exposed during a glacial period.

"At its peak, it is believed that the megaflood could have lasted several months, discharging an estimated one million cubic metres of water per second. This flow was one of the largest recorded megafloods in history and could have occurred 450,000 to 200,000 years ago," the study said.

The researchers have opined that the breach of the ridge, and subsequent flooding, reorganised the river drainages in north-west Europe by re-routing the combined Rhine-Thames River through the English Channel to form the Channel River.

The breach and permanent separation of the UK also affected patterns of early human occupation in Britain. The flooding induced changes in topography creating barriers to migration, which led to a complete absence of humans in Britain 100,000 years ago, they said.

"This prehistoric event rewrites the history of how the UK became an island and may explain why early human occupation of Britain came to an abrupt halt for almost 120 thousand years," said Dr Sanjeev Gupta, from the Department of Earth Science and Engineering at Imperial.

ANI