Giant tsunami predicted to flatten parts of US and Europe
The US coastline and much of Western Europe could be devastated by a tsunami several times worse than the one which ravaged south-east Asia a couple of weeks ago, according to research.A future eruption at the Cumbre Vieja volcano on the Canary Islands would be likely to cause a landslide on its western flank, causing a huge piece of rock twice the size of the Isle of Man to break off and travel into the sea at speeds of up to 350 km an hour.
According to the study, the disintegration of the rock would produce a debris avalanche deposit extending 60 km from the island. The energy released by this collapse would be equivalent to the electricity consumption of the whole of the United States in half a year.
The model, created by Dr Simon Day and his colleagues at UCL, predicts the landslide would create an exceptionally large tsunami with the capability to travel great distances, reaching speeds of up to 800 km an hour.
Immediately after the collapse of Cumbre Vieja, a dome of water around 900 metres high and tens of kilometres wide would form, and as the landslide continues to move underwater, a series of wave crest and troughs would be produced, soon developing into a tsunami " wave train".
After just 10 minutes, the model predicts that the tsunami could have moved a distance of almost 250 km.
The greatest effects would occur to the north, west and south of the Canaries. Waves reaching heights of 100 metres could land on the West Saharan shore, while the north coast of Brazil would encounter waves of around 40 metres.
Florida and the Caribbean would have to brace themselves for 50-metre high waves, higher than Nelson's Column in London, some eight or nine hours after the initial landslide.
Around Europe, the height of the waves would be smaller but a substantial tsunami would still hit the Atlantic coasts of Britain, Spain, Portugal and France.
Although it is not possible to make an accurate estimation, Dr Day said that the economic damage would in the multi-trillion US dollar range.
"The collapse would occur during some future eruption after days or weeks of precursory deformation and earthquakes," he stated. "An effective earthquake monitoring system could provide advanced warning of a likely collapse and allow early emergency management organisations a valuable window of time in which to plan and respond."
However, he added that the short and medium term risks were negligible as Cumbre Vieja currently was not erupting.
"Eruptions of Cumbre Vieja occur at intervals of decades to a century or so, and there may still be a number of eruptions before its collapse."
But Dr Day said that even though the year-to-year probability of a collapse was relatively low, the resulting tsunami would be a major disaster, with huge repercussions all around the world.
"Cumbre Vieja needs to be monitored closely for any signs of impending volcanic activity, as well as for the deformation that would precede its collapse," he concluded.
By Jane Kettle