March 16, 2005

scientists respond to Boxing Day Tsunami research

The research on the fault line behind the earthquake that caused the tsunami in the Indian Ocean on Boxing Day was published in the journal Nature.

Professor Nick Ambraseys, Senior Research Fellow, Imperial College, said:

“The authors conclude with what amounts to a prediction that an earthquake of magnitude 7.0-7.5 would seem to be the greatest immediate threat. However, there is nothing in their article that enables, with any degree of certainty, the prediction of the immediacy of the next earthquake, except that an earthquake of this magnitude, such as those of 1833 and 1861, is likely to occur sometime in the future. False alarms and inaccurate timing could create more problems than already exist.”

Professor Peter Styles, president of the Geological Society, said:

“It has become apparent over the last ten years that when a major earthquake occurs it changes the stress in adjacent areas. Sometimes this can serve to lock the fault, but sometimes it can make another failure more likely.

“McCloskey and his co-workers have calculated that the recent devastating Sumatra-Andaman earthquake has caused very significant stress increases on the neighbouring Sumatra fault and they predict that this increases the probability of a magnitude 7+ earthquake. This type of triggering has certainly occurred on other plate boundaries.

“However, while we cannot know ahead of time whether this would be tsunamigenic, every effort should be made to ensure that appropriate monitoring technologies and communication protocols are put in place to monitor the Indian Ocean.”

Dr Richard Teeuw, Senior Lecturer at the Geohazards Research Centre, University of Portsmouth, said:

“If another Indian Ocean tsunami were generated in the near future, there would still be great loss of life close to the earthquake epicentre. However, in regions where the tsunami will take hours (rather than minutes) to arrive, this time round there would probably be fewer fatalities caused directly by the waves. This is because people around the Indian Ocean are now well aware of what tsunamis are, what their tell-tale signs are and how best to escape them. People on the coastal lowlands seeing the initial retreat of inshore waters would either seek refuge in multi-story buildings, or flee to higher ground. That said, some people would be particularly vulnerable to the tsunami hazard: very old folk, young children and hospitalised people might not be able to escape to safe locations, especially if they are in villages on coastal plains with few higher-ground refuges.

“Unfortunately, whilst another major tsunami in the near future is likely to result in fewer direct fatalities, many more people would probably die as a result of indirect causes: tsunami-related trauma, malnutrition, infection and disease.”

On the issue of preparedness, Dr. Carmen Solana, Senior Lecturer, School of Earth and Environmental Sciences, University of Portsmouth, said:

“People have clearly not understood that the Boxing Day disaster was not due to lack of sensors in the Indian Ocean. The U.S. did manage to warn home officials in Sri Lanka but there was no response and Indian Military officials placed in the Andaman Islands warned India’s mainland of the impending tsunami, however nothing was done about it. Obviously, this disaster should have taught us that, without preparedness and a comprehensive communication and action plan, warnings are useless.

“Monitoring instrumentation is expensive, requires permanent maintenance and has a short life span. I can very easily envisage that in some five years time the money and resources to maintain most of these sensors will not be available any more and therefore the investment will have been wasted.

“If only a small proportion of the proposed investment in instrumentation was diverted to education and planning it will have a greater beneficial impact. Planning and education against disasters is a long-term investment that uses resources already existent in most of these countries to save lives.”

Notes to Editors 1) These papers will be published in Nature this Thursday (Vol.434, No.7031, 17 March, 2005).