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A huge landslide of Ice Age sediment under the Norwegian Sea 8,150 years ago (illustrated) produced a tsunami so powerful it swept hundreds of miles down the North Sea and created waves of up to 65 feet high
It was a time when stone-age hunter gatherers were spreading across northern Europe and into Britain as the glaciers of the last ice age retreated.

But just as these mesolithic tribes were settling in these newly uncovered areas a giant tsunami triggered by an underwater landslide off the coast of Norway devastated large parts of Europe.

Waves of up to 65 feet (20 metres) are thought to have smashed into Iceland, Greenland, Norway, Scotland and parts of England's northern coastline.

Scientists have now uncovered evidence that shows just how powerful these huge waves were and the huge area that they effected.


Sediment discovered on the south west coast of Denmark shows the waves spread out across the Norwegian Sea and penetrated deep into the North Sea.

Waves of at least six feet tall (2m) would have been powerful enough to sweep people off their feet if they had been unfortunate enough to be standing on the Danish coast at the time.

Writing in the journal Geology, Dr Mikkel Freurgaard, a geologist at the University of Copenhagen and his colleagues who conducted the study, said: 'Our results demonstrate that the Storegga tsunami propagated 900 - 1000 km (559-621 miles) across the shallow continental shelf of the North Sea.

'This implies that the Storegga slide tsunami probably impacted the entire coast of the southeastern North Sea.'

The tsunami is thought to have been triggered when a 120 mile long stretch of sediments that had accumulated off the coast of Norway during the Ice Age broke free of the continental shelf and plunged into the depths 8,150 years ago.

The area of seabed is thought to have been roughly the same size as Iceland and was up to 111 feet thick.

This huge underwater landslide, known as the Storegga slide, sent waves out in all directions, causing huge tsunamis to sweep over the coastline of Norway and Iceland.

The waves also raced south engulfing the Faroe Islands, Orkney and large parts of the coastline of mainland Britain.

Previous studies, however, have found that friction from the shallow seabed in the North Sea would have dissipated the tsunami's energy and so doubted it would have reached far down the west coast of mainland Europe.

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The researchers found sediment carried by the tsunami 8,150 years ago reached as far south as the island of Rømø (pictured) on the west coast of Denmark, suggesting the waves swept the length of the North Sea
The latest findings, however, which are published in the journal Geology, have shown that sediment on the island of Rømø on the west coast of Denmark, contain material carried by the powerful tsunami waves.

At the time sea levels would have been 65 feet (20m) lower than they are currently and the area was covered by a large lake.

Dr Freurgaard told Science Nordic: 'At some point there was a big inundation of sea water, which dumped a lot of marine sand at the bottom of the lack, along with (organic) material from the edges of the lake and the lake bottom.'

Nicolai Kliem, head of the sea and ice section at the Danish Meteorological Institute in Copenhagen who was not involved in the study, added: 'The fact the tsunami reached Denmark suggests that it was very strong.'