Mega tsunami with 65ft waves may have wiped out Stone Age populations in Britain

There were also likely indirect impacts caused by damage to key resources, scientists say

A mega-tsunami with gigantic waves reaching up to 65 feet submerged large parts of Northern Europe over 8,000 years ago and led to a massive dip in Stone Age Britain’s population, a new study says.

The massive tsunami was caused by an underwater landslide known as the Storegga slide near Norway and coincides with a time when there was a large population decline in northern Britain, researchers from the University of York say.

Previous research suggested that during this time northern Britain had a small population of about 1,000 people and any giant tsunami of this size may have devastated these Stone Age coastal communities.

While archaeological records suggest that the number of sites inhabited across northwest Europe suddenly plummeted around this time, this has also been linked to a rapid and sustained drop in temperatures across the continent.

But the new study, published recently in the Journal of Quaternary Science, points out that the Storegga tsunami also coincides with this massive population decline between about 8,120 and 8,175 years ago.

The massive landslide off the coast of western Norway displaced 2400–3200 cubic km of sediment, and may have triggered waves reaching heights of about 3 to 6m (10 to 20ft) in northern England with monster waves of over 20m (65ft) battering Shetland Islands that lie to the north of the Scottish mainland, scientists say.

In comparison, the 2004 Indian Ocean tsunami that killed over 230,000 people reached a maximum height of about 167ft (51m), according to the US National Oceanic and Atmospheric Administration (NOAA).

In the new study, researchers carried out computer simulations of the tsunami and assessed whether the massive waves contributed to the population decline and sediment deposits formed during this period, or if other factors played more significant roles.

The simulations suggest sediment deposits from the ancient site of Howick in Stone Age Britain could have been formed by the tsunami, although only if the waves struck during high tide.

While past fishing societies in tsunami-prone regions such as the Northern Pacific have shown some resilience to tsunamis, moving to higher ground, researchers suspect this is unlikely to have been the case for the Stone Age people in Britain who would have had “no living memory of tsunamis and no appreciation of the danger as the sea receded.”

Based on the simulation, scientists suspect there could have been significant mortality due to the tsunami as well as indirect impacts caused by damage to key resources that the ancient people needed to survive.

“At Howick, the tsunami’s impact is shown to be severe with potentially catastrophic direct mortality as well as longer-term impacts on resource availability for survivors,” researchers wrote in the study.