Britain could be hit by 30ft wave, says top scientist

Britain could be devastated by a tsunami similar to the one that killed more than 120,000 people around the Indian Ocean last week, the Government's chief scientist warns today.

Meanwhile a secret government exercise has demonstrated that a tidal surge in the North Sea could breach sea defences, causing death and destruction from Yorkshire to Devon.

Writing exclusively in today's Independent on Sunday, Professor Sir David King calls for a tsunami early warning system in the north Atlantic. In a warning that will resound around Westminster and Whitehall, Sir David writes that it is "likely" that a mass of rock the size of the Isle of Man will "collapse" into the sea around the Canary Islands. He adds: "We would have a six-hour warning before a wave of around thirty feet in height hit us."

The problem, he says, is that no one knows when it will happen; it could be "any time between now and the next 10,000 years". However, he says now is the time to establish a warning system.

He also calls for governments worldwide to set up a scientific panel to develop a "global foresight programme" to co-ordinate research on catastrophes caused by earthquakes.

The secret exercise - called Operation Triton - was carried out in Britain last autumn to test the response to a catastrophic storm surge like the one that flooded East Anglia in 1953, killing 307 people. Government studies have concluded that surges are increasing as global warming takes hold.

Operation Triton created a scenario of the aftermath of a fictional "Hurricane Somers" veering across the Atlantic. It found it creating a nine-and-a-half-foot-high surge, breaching sea defences around the coast from the Humber to the Exe, driving the sea up to six miles inland. Roads were blocked, causing traffic chaos; power failures plunged whole areas into darkness; and many thousands of people had to be evacuated.

The exercise found that government departments and emergency services worked well together and that warning systems were adequate, but raised concerns about whether people would be willing to leave their homes.

The Environment Agency is planning to contact the million homes and businesses at risk, warn them that they could be flooded from the sea and ask them to think out what they would do in an emergency.

Yesterday its chief executive, Baroness Young of Old Scone, told The Independent on Sunday: "It would not take a tsunami, it would just need a very big North Sea surge and we would have to evacuate. We have got the warning system, but the question is whether people would move in time."