Acehtsunami

There is no way to stop a tsunami once set in motion, but there are ways to avoid getting killed by one. The Japanese government has invested billions in coastal defenses against tsunamis — for example, building concrete sea walls to blunt the impact of the waves and gates that slam shut to protect harbors. But for large tsunamis, the rule is this: You can run, but you can’t hide. So tsunami hazard experts are working on ways to make sure people know when a tsunami is coming and where they can run to get out of harm’s way.

In Japan and the United States, the foundation of tsunami warnings systems is the seismometer. When officials detect a large, shallow earthquake under the ocean, they issue a warning. But this method is plagued by false alarm