A landslide off Norway 8000 years ago triggered a 4-metre-high tsunami that swamped Scotland

Was caught by a paragraph in a New Scientist article on 'Fuel of the Future?' Methane hydrates [ Fuel of the future: How fiery ice could power Asia - environment - 07 March 2013 - New Scientist ]

Ancient history offers evidence to support this, says Euan Nisbet of Royal Holloway, University of London. A landslide off Norway 8000 years ago triggered a 4-metre-high tsunami that swamped Scotland. Geological data suggests it was accompanied by a massive methane release, possibly because warmer temperatures melted sea-floor hydrates (Nature, doi.org/ccf5rs).

Which got me thinking about 8000 years ago - or 8,200 years ago as some other sources say

One recent study has discovered that, according to radiocarbon dating of sediments from the area, a 'giant tsunami' hit the eastern coast of Scotland in 5,800 BC. Stone tools found in the sand off Inverness showed that the waves hit the area without warning following a landslide off Storegga in north-west Norway.

Professor Smith, of the Department of Geography at Coventry University, told BBC News Online:

"It looks as if those people were happily sitting in their camp when this wave from the sea hit the camp. Professor Smith of the department of Geography at Coventry University told BBC News Online. We're talking about two, three or four large waves followed by little ones, that would have been 5-10 metres high. These waves do strike with such force that they are very destructive. It's like being hit by an express train'."