None of the countries most severely affected – including India, Thailand, Indonesia and Sri Lanka – had a tsunami warning mechanism or tidal gauges to alert people to the wall of water that followed a massive earthquake, said Waverly Person of the USGS National Earthquake Information Centre.

“Most of those people could have been saved if they had had a tsunami warning system in place or tide gauges,” he said yesterday. . . .

US seismologists said it was unlikely the Indian Ocean region would be hit any time soon by a similarly devastating tsunami because it takes an enormously strong earthquake to generate one.

“That’s really what has created all of these problems – is that the earthquake is just so massive,” said Dan Blakeman, a USGS earthquake analyst.

But Person said governments should instruct people living along the coast to move after a quake. Since a tsunami is generated at the source of an underwater earthquake, there is usually time – from 20 minutes to two hours – to get people away as it builds in the ocean.

“People along the Japanese coasts, along the coasts of California – people are taught to move away from the coasts. But a lot of these people in the area where this occurred – they probably had no kind of lessons or any knowledge of tsunamis because they are so rare.”

Like an asteroid strike, it seemed too unlikely to be worth guarding against.