Cardiff researcher proposes anti-tsunami concept

Sound waves could be used to dissipate the energy of tsunamis and potentially save lives, according to a researcher from Cardiff University.

(Credit: Dr Usama Kadri)

In the journal Heliyon, Dr Usama Kadri, from the university's School of Mathematics, outlines how acoustic-gravity waves (AGWs) could be fired at a tsunami to reduce its amplitude, or height. AGWs are natural sound waves that travel in the oceans, sometimes thousands of metres below the surface. If we could find a way to engineer these waves, we could use them to diminish the energy of tsunamis and protect populations living in coastal areas.

The proposed system would involve two AGWs fired at the tsunami's epicentre to form what's known as a resonant triad. Research suggests that mitigation of surface gravity waves (tsunamis) is possible through a careful resonant triad interaction.

"Within the last two decades, tsunamis have been responsible for the loss of almost half a million lives, widespread long-lasting destruction, profound environmental effects and global financial crisis," said Dr Kadri.

"Up until now, little attention has been paid to trying to mitigate tsunamis and the potential of acoustic-gravity waves remains largely unexplored."

The 2004 Boxing Day tsunami killed over 230,000 people in 14 countries, and the energy released by the earthquake that caused it was estimated to be the equivalent of approximately 1,500 Hiroshima bombs. In order to use AGWs in tsunami mitigation, engineers would first need to develop highly accurate AGW frequency transmitters or modulators, which Dr Kadri admits would be difficult.

"In practice, generating the appropriate acoustic-gravity waves introduces serious challenges due to the high energy required for an effective interaction with a tsunami,” he explained.

“However, this study has provided proof-of-concept that devastating tsunamis could be mitigated by using acoustic-gravity waves to redistribute the huge amounts of energy stored within the wave, potentially saving lives and billions of pounds worth of damage."