Michael Richardson: Support builds for Indian Ocean tsunami alert system

Killer waves triggered by undersea earthquakes have been relatively rare in the Indian Ocean. But the enormity of the disaster following last week's massive upheaval off Indonesia has shocked governments around the region and created an official groundswell of support for an international tsunami warning system similar to one that has long operated in the Pacific.

Commonwealth Secretary-General Don McKinnon is among those who have called for such a system. Australia's Foreign Minister, Alexander Downer, said Canberra was launching an initiative to establish a co-ordinated alert network for the Indian Ocean area that could help save lives and minimise damage from future tsunamis.

Officials and scientists in Asia, Europe and the United States have also called for a co-ordinated warning system. This increasingly widespread support makes it more likely that the considerable costs can be met of installing equipment in different countries, linking it together using computers and modern communications, and maintaining the network so that it works effectively.

As the death toll in many Asian countries from the giant waves continues to rise, the survivors all tell a similar tale of seeming normalcy followed by a sudden wall of water rising from the sea and smashing its way up to several hundred metres inland from the coast.

The many thousands who died in at least 10 nations in and around the Indian Ocean, and the hundreds of thousands more who lost their homes and livelihoods, received no warning of the looming disaster.

Yet on the other side of Asia, in the Pacific, there is a long-established and well-tested international system for alerting countries of dangerous tsunamis, the fast-moving waves that can be set in motion when the geological plates that form the foundations of major land masses collide.

"Most of those people could have been saved if they had had a tsunami warning system in place or tide gauges," said Waverly Person, a scientist at the National Earthquake Information Centre in Washington, an arm of the US Geological Survey. Of course, it is easy to be wise after the event. This was the world's most powerful earthquake in 40 years, and the fourth or fifth biggest in the last century. Unlike some volcanic eruptions, it could not be predicted.

And as Person noted, tsunamis are rare in the Indian Ocean compared with the Pacific. In the latter during the 101-year period from 1900 to 2001, nearly 800 tsunamis were recorded; 117 caused casualties and damage, most near the source only. But at least nine caused widespread destruction throughout the Pacific.

Scientists estimate that the tsunami, travelling at speeds of up to 800km/h, took at least two hours to reach Sri Lanka and India, more than long enough for an alert to have been given had a system like that based in the Pacific Tsunami Warning Centre in Ewa Beach, Hawaii, been in operation.

The centre was established in 1949. But it only became the hub of a formal arrangement in 1965, when it assumed the international warning responsibilities of the Pacific Tsunami Warning System. The PTWS's 26 member states include New Zealand, Australia and other Pacific nations.

The aim of the Pacific warning system is to detect and locate major earthquakes in the region, to determine whether they have generated tsunamis, and to provide timely and effective tsunami information and warnings to the population to minimise the hazards of seismic waves.

To achieve this objective, the network continuously monitors seismic activity and ocean surface levels in the Pacific basin. It does so by linking earthquake sensing stations and tide gauges throughout the region. Rapidly locating and estimating the size of earthquakes is important. The alarm thresholds at the centre in Hawaii are set so that a tremor registering 6.5 or more on the Richter scale anywhere in the Pacific area will activate them.

However, scientists say that the size of tsunamis often cannot be estimated with complete confidence based on earthquake data alone. Automatic tide gauges that record unusual rises and falls in sea-level near the epicentre of the earthquake help to fill out the picture.

It would take time, probably at least a year, to establish a tsunami warning system in the wider Indian Ocean region. Whether it would be effective in giving people in vulnerable areas sufficient warning to move to higher or safer ground would depend on public education and the ability to spread any warnings quickly through local authorities. This works in many parts of the Pacific but may not work in Indian rim countries with poor communications.

But even without expensive ocean sensors and computer modelling, public education programmes about tsunamis can save lives. Other obstacles to an effective multinational alert network for the Indian Ocean region include political divisions.

One way of putting a warning system in place may be to work through the Indian Ocean Rim Association for Regional Cooperation. The association has 18 member states: Australia, Bangladesh, India, Indonesia, Iran, Kenya, Madagascar, Malaysia, Mauritius, Mozambique, Oman, Singapore, South Africa, Sri Lanka, Tanzania, Thailand, the United Arab Emirates and Yemen.

One of the good things to emerge from the tsunami disaster is that countries in the Indian Ocean region that have had tense relations in the past have been drawn together by their common suffering.

* The writer, a former Asia editor of the International Herald Tribune, is a visiting senior research fellow at the Institute of Southeast Asian Studies in Singapore.