Technology Versus Tsunamis

A tsunami can strike quickly after an earthquake, reports CBS News Correspondent Barry Petersen.

Tsunamis start when an undersea earthquake triggers waves of up to 500 miles an hour -- in the deep ocean it's barely a ripple. In the shallows, close to land, the waves swell and that power can become a wall of water a hundred feet high or more.

Some villages pin their defense on sea walls with gates, able to close on a moment's notice. Tokyo has also invested millions to beat back tsunamis.

The Japanese know that walls aren't the only answer. Far better, they say, to give people some warning, even if its only a few minutes so they can run for the hills. To make it possible, the Japanese are turning increasingly to what they do best - hi tech.

At regional tsunami centers, in fact, sophisticated computers analyze every earthquake so officials can raise the alarm before the roar of a tsunami comes to claim its next victims.

More from CBS News