The ‘Storegga slide’ — an underwater collapse 8,200 years ago that triggered a massive tidal wave — destroyed 373 miles of Scotland’s coastline, a study finds.
Had it happened today, with our higher sea level, it would have destroyed some of all the cities such as Aberdeen, Inverness, Arbroath, Montrose, Stonehaven and Wick.
They all have significant built-up areas that are just 10 meters above sea level and directly overlook the coast – making them vulnerable to such tsunamis.
The 30m wave, which caused the UK’s worst natural disaster in 11,000 years, was triggered by a 36,680 square mile landslide in the Norwegian Sea.
Researchers led by Sheffield University analyzed and dated sediment deposits left behind by the ancient tsunami to model the wave’s impact on the Scottish coast.
This allowed them to reveal for the first time that the monstrous wave managed to travel up to 30 kilometers inland at some locations.
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The ‘Storegga slide’ — an underwater collapse 8,200 years ago that triggered a massive tidal wave — destroyed 373 miles of Scotland’s coastline, a study finds. Pictured: The sites around the coasts of Scotland where the Storegga tsunami left sediment deposits
Researchers led by Sheffield University analyzed and dated bedrock deposits left behind by the ancient tsunami to model the wave’s impact on the Scottish coast. Pictured: Their model of the Montrose Basin – just north of Dundee, on the east coast of Scotland, as visible on the previous map) showing the extent of the coastal inundation by the gulf (in darker blue, showing the study site in Maryton labeled with a star). An animation of the impact of the tsunami on this area can be seen below (in which the Maryton site is marked with a blue cone. Note that the video is shown with the north axis facing the lower left corner
“Although the Storegga Tsunami has been known for years, this is the first time we have been able to model how far inland from the Scottish coast the tsunami wave traveled,” said author Mark Bateman of the University of Sheffield.
While there is currently no comparable threat from Norway, the UK could still be at risk of flooding from potential volcanic eruptions around the world, such as those predicted in the Canary Islands.
“These would create a similar tsunami wave because of the amount of material that would be displaced by the volcano.
“These models give us a unique look at the past to see what the country was like, and how it can be influenced again.”
The Storegga tsunami was caused when submarine glacial and interglacial sediments shifted on the coastal slopes of the Norwegian continental shelf.
In their study, Professor Bateman and colleagues study deposits in Maryton in Aberdeenshire, dating the sediments using luminescence techniques.
This allowed them to determine the age, number and relative strength of the tsunami waves that had hit the Scottish coast.
The Storegga tsunami was caused when submarine glacial and interglacial sediments shifted on the coastal slopes of the Norwegian continental shelf. Pictured: A map showing the source of the Storegga tsunami (in dark blue) with estimates of wave heights at various locations in yellow. The red circle represents the study site of Montrose Basin in the east of Scotland
The 30-meter wave – which caused the UK’s worst natural disaster in 11,000 years – was caused by a 36,680 square mile landslide in the Norwegian Sea. Pictured: A model of the tsunami as would have been recorded in eastern Scotland, based on modern bathymetry
Pictured: A tsunami wave map showing the distribution of the first (upper) and second (lower) waves hitting the UK coastline
‘Thirty years ago, identifying the flooding of the Storegga tsunami’ […] was groundbreaking in recognizing that undersea landslides pose a major threat,” said Dave Tappin of the British Geological Survey, who was not involved in the current study.
The new research, he added, “provides important new insights into understanding the flooding from the Storegga tsunami.”
“The research emphasizes the importance of applying new scientific techniques to older events studied, increasing our understanding of their impact.”
The study’s full findings were published in the journal Boreas.
THE STOREGGA UNDERWATER LANDSIDE — THE BASIS
The seafloor can collapse as physical conditions change, just like on land, causing a landslide underwater.
These massive movements of large amounts of sediment are called submarine landslides or ‘slides’.
The sea covers more than 70 percent of the planet, so there are probably many more landslides at sea than on land.
Undersea landslides can be found even at very low slope angles – as low as 1°, and mapping them underwater is difficult and expensive.
More than 8,000 years ago, a massive undersea landslide occurred off the coast of Norway.
This Storegga Slide resulted in a tsunami hitting the north east coast of Great Britain.
The area of the Storegga Slide is about the size of Scotland.
About 791 cubic miles (3,300 cubic kilometers) of sediment slid down — much of it as large blocks, up to a mile wide.
Previous studies have shown that similar events have occurred in this area about every 100,000 years.
However, new findings from a recent University of Dundee study suggested that smaller underwater landslides may be much more common.