Experts have found that large areas of Norfolk were devastated by a North Sea mega-tsunami 8,000 years ago - and it could happen again.
Researchers from the University of Bradford have found fresh evidence that the cataclysm happened around 8,150 years ago, sending waves at least 40km inland from the Norfolk coast - which was then much further out than it is today.
And they warned that the event that triggered the mega-tsunami - a shifting of the seabed known as the Storegga Slide - could repeat itself as temperatures rose through climate change.
Dr Simon Fitch, from the university’s school of archaeological and forensic sciences, said the huge wave caused by the shift of Storegga - an area of seabed off Norway which is about the size of Scotland - happened during a period of global climate change.
Dr Fitch said: “It’s not beyond the realm of possibility that it could happen again.
“One of the things [Storegga] has is gas hydrates, and they can become unstable when temperature rises. That would effectively cause another landslide.
“There are big ‘coulds’ but it’s serious enough that the Netherlands and some other countries have done investigative studies into it. Global warming does make me concerned that we are making conditions more favourable for it to occur.”
Dr Fitch said the power of such a wave - even if it “only” reached 20km inland from The Wash and north Norfolk, would be “phenomenal”.
Norfolk was once connected to mainland Europe by an area known as Doggerland, which gradually receded between 16,000 and 7,000 years ago.
Dr Fitch said that when the mega-tsunami hit, Norfolk bulged upward to the Humber estuary. “It would have been greater Norfolk and Yorkshire then,” he said.
Groundbreaking evidence of the wave has just been released by the university, after a couple of years’ study of a core taken about 40km off the coast of north Norfolk.
This core - a six-metre long cross-section of earth from beneath the seabed - confirmed the tsunami happened, and gave insights into what the Doggerland landscape that now lies underwater off the Norfolk coast once looked like.
MORE: ‘How I found prehistoric human footprints’ - Norfolk man tells of amazing beach findDr Fitch said: “We drilled a large plastic pipe into the ground and recovered a very interesting core. The sequence had some unique and distinctive tsunami deposits in it, and this is the first core which has come from the North Sea which has the tsunami marker.
“It was cored a couple of years back but it has taken this long to get all the data together - extraordinary evidence needs extraordinary proof.”
At the time the tsunami hit Doggerland, a Mesolithic hunter-gatherer people could have been living in the area. Modelling suggests that much of the landscape may have returned to pre-tsunami conditions - but its longer-term fate was to be submerged as sea levels rose to those of the present day.
Dr Fitch said researchers extracted DNA of tree species including ash, elm, pine and oak from the core, which would have been left as the water from the tsunami receded.
He said: “The area where the core was taken was an estuary, but it goes to show the landscape surrounding the estuary was quite heavily wooded.”
MORE: Will the secrets of Doggerland - once Norfolk’s ‘neighbour’ - be revealed by North Sea discovery?The research was carried out as part of a multi-university project called Europe’s Lost Frontiers, which is looking into Doggerland and the hunter-gatherer societies that once lived there.
The project’s principal investigator, Prof Vince Gaffney, also from Bradford, said: “Exploring Doggerland, the lost landscape underneath the North Sea, is one of the last great archaeological challenges in Europe.
“This work demonstrates that an interdisciplinary team of archaeologists and scientists can bring this landscape back to life and even throw new light on one of prehistory’s great natural disasters, the Storegga tsunami.
“The events leading up to the Storegga tsunami have many similarities to those of today. Climate is changing and this impacts on many aspects of society, especially in coastal locations.”
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