Deep ocean sound waves may aid tsunami detection

​Boston: Scientists are developing a system that may help predict a tsunami by detecting sound waves that race through the deep ocean more than 10 times faster than the more destructive wave. "Severe sea states, such as tsunamis, rogue waves, storms, landslides, and even meteorite fall, can all generate acoustic-gravity waves," said Usama Kadri, a research affiliate at Massachusetts Institute of Technology's (MIT).

"We hope we can use these waves to set an early alarm for severe sea states in general and tsunamis in particular and potentially save lives," Kadri said. Acoustic-gravity waves are very long sound waves that cut through the deep ocean at the speed of sound. These lightning-quick currents can sweep up water, nutrients, salts, and any other particles in their wake, at any water depth.

They are typically triggered by violent events in the ocean, including underwater earthquakes, explosions, landslides, and even meteorites, and they carry information about these events around the world in a matter of minutes. Researchers at MIT have now identified a less dramatic though far more pervasive source of acoustic-gravity waves - surface ocean waves.

These waves, known as surface-gravity waves, do not travel nearly as fast, far, or deep as acoustic-gravity waves, yet under the right conditions, they can generate the powerful, fast-moving, and low-frequency sound waves.