Mathematical tsunami

A new mathematical formula that could be used to give advance warning of where a tsunami is likely to hit and how destructive it will be has been developed by scientists at Newcastle University.

The research, led by Newcastle University’s Prof Robin Johnson, was prompted by the 2004 Boxing Day tsunami disaster, which devastated coastal communities in Indonesia, Sri Lanka, India and Thailand.

In that case, an earthquake in the depths of the ocean triggered a long surface wave that resulted in six massive wave fronts, one after the other.

Of these waves, it was the third and largest one that caused the most devastation, hitting the beaches with terrifying speed. Reaching a height of 20m, it was this wave that lifted a train from its tracks as it travelled along the Sri Lankan coastline, killing almost 1,000 people.

The new research shows that the number of peaks and troughs in the initial disturbance out at sea dictates the number of wave fronts that will steepen and eventually produce tsunami waves.

Johnson said that by calculating the number of waves that will coalesce or ‘join together’ as the faster ones catch up the slower ones, it is possible to predict how many and how big and fast the final waves hitting the shoreline will be.

He added: 'We have shown that it is possible to use the initial wave pattern to work out how the wave will evolve and, importantly, how it might interact with the complicated motions close inshore to produce the tsunamis that we experience.

'With a time delay of maybe two or three hours between the initial wave trigger and the tsunami hitting the shore, this could prove vital.'