Tsunami alert missing vital details

If another big tsunami rolls across the Indian Ocean today, it would probably be detected and threatened nations alerted, the head of the UN body developing such a warning system says.

But the system cannot determine whether a tsunami would merely ripple onto sun-spangled beaches of the Indian Ocean rim or turn into monster waves wiping out towns and villages.

"Yes, we can confirm the presence of a tsunami today," says Patricio Bernal, executive secretary of UNESCO's Intergovernmental Oceanographic Commission (IOC), which is spearheading an Indian Ocean tsunami warning system.

Pacific tsunami warning centres in Tokyo and Honolulu now have a network of experts to contact around the clock in Indian Ocean nations when seismographic data indicates an earthquake that could cause a tsunami.

A string of tidal gauges the IOC is maintaining off northwestern Sumatra, Diego Garcia and the coast of Mauritius can detect a tsunami. And Indian Ocean nations are setting up mechanisms to exchange data and warnings.

Minimising false alarms
What the system can't do is minimise the many false alarms that come with sizeable earthquakes on the seabed that do not trigger a big tsunami or even cause damage on land.

That's crucial because emergency coordinators must know when to sound the alarm that will set in motion costly mass evacuation plans.

"It's insufficient, yes," Bernal says, on the margins of the first meeting of the Indian Ocean Tsunami Warning and Mitigation System in the Western Australian city of Perth.

"But at least we can confirm it now and that's something we couldn't do even at the end of March," he says.

There were no tsunami warning systems when the strongest earthquake in 40 years struck off the coast of Sumatra on 26 December, triggering a record tsunami that is feared to have killed as many as 232,000 people in a dozen Indian Ocean nations and left more than a million homeless.

A second, more expensive system targeted for completion by next July will involve installing a series of pressure gauges on the sea bottom that would more accurately, and far more quickly, detect the approach and direction of a big tsunami.

Tens of thousands of lives might have been saved if such a system had been in place before the December catastrophe.

"We would have saved all the people in Sri Lanka, India and the Maldives at least, because the wave took two hours to reach there," Bernal says.

Regional warning centre
Five countries in the region (Thailand, India, Indonesia, Australia and Malaysia) have offered competing proposals to host a regional tsunami warning centre.

Bernal says no decision on that politically sensitive topic would come at the Perth meeting, and he saw no problem having more than one centre anyway.

"It's like the military," one diplomat at the conference said. "You build in redundancy. We'll end up with several nodes, but the thing is to confer with each other."

This week's meeting, which ends today, will help to determine how warnings would be standardised and communicated, how seismic data can be collected and exchanged, and how technology can be transferred, among other things.

With tsunami warning systems now in the works for the Mediterranean and the Caribbean regions, the Indian Ocean system could become a global model, a far cry from seven months ago when few people even knew what a tsunami was, the diplomat says.

Source: abc.net.au