The massive killer tidal wave would be created by a huge slab of rock – twice the size of the Isle of Man – smashing into the Atlantic Ocean after breaking away from the island of La Palma.
The monster wave, higher than Nelson’s Column and travelling faster than a jet aircraft, would dwarf anything humans have ever seen.
The fallout on the coastlines of Florida, US, and Brazil would be catastrophic, as most of the waves’ energy – equal to six months’ worth of US power station output – travels westwards across the Atlantic Ocean.
But the UK would not escape the carnage, according to a top scientist who has studied the effects of a future volcanic eruption in the Canary Islands.
Research from Dr Simon Day, of the Institute for Risk and Disaster Reduction at University College London, found that if the Cumbre Vieja – an active but dormant volcano – were to erupt, the western flank of the mountain could tumble into the sea.
He told Daily Star Online the monster volcano has erupted roughly once every 50 to 70 years on average, each time raising the probability of a collapse.
It last erupted in 1971, meaning another violent outburst of lava could be due within the next three years.
This eruption could cause the landslide, which will unleash a deadly wall of water, initially almost 3,000ft high and several miles wide, to hurtle towards the UK’s southern shores.
However, Day stressed that it’s more likely that the collapse will happen “some time in the next several thousand years”, estimating that the Cumbre Vieja is “more than halfway through its period of pre-collapse instability”.
He said: “The ‘will a collapse occur?’ dice are rolled about once every 70 years, and maybe once every 50 years at the moment.
“We do not know the probability of a collapse, nor if and by how much it increases with each eruption.
“However, the distinctive reconfiguration of the volcano during the last several thousand years is similar to those that have occurred before previous collapses at La Palma and other volcanoes.
“The key thing is that this is a low-probability but high-consequence hazard.”
The West Saharan coast of Morocco would be its first target, as the wave, measuring an impressive 330ft, would batter its shores at speeds of up to 500mph.
In just nine hours, the tsunami would then lurch 3,906 miles across the Atlantic Ocean at break neck speed.
Although Florida and the Caribbean would suffer the greatest destruction, with waves up to 164ft smashing their coastlines, a weaker, but still massively destructive wave, is likely to batter Britain.
It is thought thousands of people living in Britain’s southernmost coastal cities and towns, including Cornwall, Devon and Portsmouth, could be wiped out within hours, assuming no effective evacuation.
However, due to the uncertainties of tsunami modelling, Dr Day said the exact number of casualties is difficult to estimate.
He said: “For low-lying land along the south coast it could penetrate up to a mile.”