Weatherwatch: storm waves that can roll great slabs of rock
Winter storms battering the British Isles are more powerful than often assumed. The stormy winter of 2013-14 along the west coast of Ireland produced waves so powerful they tore great slabs of rock out of coastlines and shoved them inland. Among those boulders was a 620-tonne colossus, equivalent to more than three blue whales, which was shoved several feet inshore, setting a new world record for the largest boulder ever known to have been moved by storm waves.
Scientists from Williams College, in Massachusetts, examined photos of shorelines before and after the violent storms and discovered many coastal sites had been completely rearranged. Boulders the size of houses and weighing 100 tonnes or more had been lifted up by waves, tilted over and bulldozed along cliff tops or shorelines, up to 220 metres (722ft) inland and up to 29 metres (95ft) above high water. It was a shocking revelation – previously it was thought that only tsunamis had the power to move such huge rocks.
The study published in Earth-Science Reviews also revealed that the storm waves had created many of the boulders by tearing the rocks out of cliffs, or peeling them out of rocky shores.
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