'Megaflood' divided Britain from Europe
A huge flood made Britain an island by breaching a narrow strip of land that linked it to mainland Europe, according to research from Imperial College London.
Using high-resolution sonar waves, a team of geographers led by sedimentologist Dr Sanjeev Gupta and marine geologist Dr Jenny Collier, captured detailed imagery of the sea floor, revealing a well-preserved landscape of deep valleys, which they believe were caused by the sudden release of large volumes of water between 200,000 and 450,000 years ago.
According to the team’s findings, published inthe journal Nature, the torrents of water probably came from a huge lake that formed in the area known today as the southern North Sea. Fed by the ancient Rhine and Thames rivers, the lake was enclosed by glaciers to the north, Britain to the west, continental Europe to the east, and a narrow limestone isthmus known as the Weald-Artois ridge – which is believed to have stood 30 metres above sea level – to the south.
A rise in the lake’s level caused the ‘megaflood’, which carved a huge valley in the Weald-Artois ridge. An estimated one million cubic metres of water per second were discharged through the ridge, inundating the land behind for several months, reorganising the river network of northwest Europe and creating what is now known as the English Channel.
Dr Gupta said: ‘This prehistoric event rewrites the history of how Britain became an island and may explain why early human occupation of Britain came to an abrupt halt for almost 120,000 years.’
October 2007
Using high-resolution sonar waves, a team of geographers led by sedimentologist Dr Sanjeev Gupta and marine geologist Dr Jenny Collier, captured detailed imagery of the sea floor, revealing a well-preserved landscape of deep valleys, which they believe were caused by the sudden release of large volumes of water between 200,000 and 450,000 years ago.
According to the team’s findings, published inthe journal Nature, the torrents of water probably came from a huge lake that formed in the area known today as the southern North Sea. Fed by the ancient Rhine and Thames rivers, the lake was enclosed by glaciers to the north, Britain to the west, continental Europe to the east, and a narrow limestone isthmus known as the Weald-Artois ridge – which is believed to have stood 30 metres above sea level – to the south.
A rise in the lake’s level caused the ‘megaflood’, which carved a huge valley in the Weald-Artois ridge. An estimated one million cubic metres of water per second were discharged through the ridge, inundating the land behind for several months, reorganising the river network of northwest Europe and creating what is now known as the English Channel.
Dr Gupta said: ‘This prehistoric event rewrites the history of how Britain became an island and may explain why early human occupation of Britain came to an abrupt halt for almost 120,000 years.’
October 2007
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