Scientist Bill McGuire told a news conference on natural disasters this week that some time in the next few thousand years the western flank of the Cumbre Vieja volcano on the Canary Island of La Palma will collapse, sending walls of water 100 meters high racing across the Atlantic.

A chunk of the volcano the size of a small island began to slide into the ocean in 1949. There is almost no monitoring of the volcano, giving virtually no chance of any advance warning of another eruption which could trigger the catastrophe.

"The U.S. government must be aware of the threat. I am sure they are not taking it seriously," McGuire of the Benfield Grieg Hazard Research Center told reporters. "They certainly should be worried, as should the island states of the Caribbean."

He said the giant tidal wave or Tsunami triggered by such a collapse would hit the other islands of the Spanish-owned Canaries within an hour and reach the north African coast within two hours.

Between seven and 10 hours later, waves still several tens of meters tall and traveling at the speed of a jet plane would be swamping the Caribbean and crashing into the eastern seaboards of South and North America.

McGuire urged the governments of Spain and the United States to fund monitoring of the volcanically active La Palma - a project he said could be achieved relatively cheaply.

He said the slow collapse - started by an eruption in 1949 - would almost certainly be turned catastrophic by another eruption of the volcano which erupts every 25 to 200 years.

The last eruption was in 1971, and prior to 1949, the previous eruption was in 1712.

"A future president of the United States must make a call on what to do when La Palma collapses," he said.

On a brighter note, scientist Benny Peiser of John Moores University in Liverpool told the same news conference that the threat of a cataclysmic strike on the earth by a large asteroid was fading rapidly as money was pumped into finding them.

Within 10 to 30 years, all the near-earth asteroids will have been charted. Scientists believe they can find a way to steer an asteroid out of the way of the earth, as long as they have enough warning it is coming.

That leaves the field clear for Hollywood to move on to volcanic eruptions and tsunami for the next generation of apocalyptic movies.