Tsunami 'could devastate Scottish towns if it happened today'

A tsunami that hit Scotland around 8200 years ago could devastate entire towns if it happened today, according to new research.

The Storegga tsunami, which affected 373 miles (600km) of coastline, was caused by the shifting of glacial and interglacial sediments on the coastal slopes at Storegga, along Norway’s continental shelf in the Norwegian sea, which displaced water and triggered the event.

Researchers have now modelled the inland impact of the ancient wave, which is considered the largest natural catastrophe to happen in the UK in the last 11,000 years.

The models that show the wave, reaching up to 98ft (30m) in height, would have travelled up to 19 miles (30km) inland along the Scottish coast and would have devastated areas such as Montrose in Angus, a town of around 12,000 people with a coastal lagoon and nature reserve.

The study was led by researchers at the Universities of Sheffield, St Andrews and York.

Lead author Professor Mark Bateman, from the University of Sheffield’s Department of Geography, said: “Although the Storegga tsunami has been known about for years, this is the first time we have been able to model how far inland from Scotland’s coastline the tsunami wave travelled by analysing the soil deposits left by the wave over 8,000 years ago.

“Though there is no similar threat from Norway today, the UK could still be at risk from flooding events from potential volcanic eruptions around the world, such as those predicted in the Canary Islands.

“These would cause a similar resulting tsunami wave due to the amount of material that would be displaced by the volcano.

“These models give us a unique window into the past to see how the country was, and could be affected again.”

Used sedimentology and dating tsunami sediment deposits at Maryton, Aberdeenshire, using luminescence, researchers were able to determine the age, number and relative power of the tsunami waves.

Commenting on the study, Professor Dave Tappin, of the British Geological Survey, said: “Thirty years ago, identifying the Storegga tsunami flooding, that struck the coast of eastern Scotland over 8000 years ago, was seminal in recognising that submarine landslides are a major hazard in triggering significant flood events.

“From the Montrose area, the new detailed analysis of the sediments deposited by the tsunami wave and their age dating using novel methods, together with the new numerical tsunami modelling of the wave impact on land, provides important new insights into the understanding of the Storegga tsunami flood.

“The research highlights the importance of applying new scientific techniques to older-studied events, thereby improving our knowledge of their impact.”

– The research is published in the journal Boreas.