It was 10:23am at the Joint Australian Tsunami Warning Centre in Melbourne, and Lindsay Gilbert was speaking to colleagues in WA about a large tsunami heading for Australia, generated by a massive earthquake near Indonesia.

Science Officer Vivek Nagar was checking the information against the Bureau of Meteorology’s computer models, while the media team were busily distilling mountains of information into a few key points.

Preliminary information showed the earthquake had a magnitude of 8.1. Within an hour that was revised up to 9.1.

Luckily, this was not a real emergency but an elaborate simulation designed to test the Indian Ocean Tsunami Warning and Mitigation System.

IOWAVE14, as the exercise was known, involved 24 countries around the Indian Ocean Rim.

In Australia several agencies took part, including Geosciences Australia, the Australian Federal Police, the Australian Maritime Safety Authority, the Attorney General’s Department, the Australian Antarctic Division, state-based emergency services and the ABC.

The simulation saw most of coastal WA affected by Land Threat warnings, the highest level of warning for a tsunami.

Rick Bailey, head of Tsunami Warning and Ocean Forecast Services at the Bureau of Meteorology, said the exercise simulated one of the largest natural disasters Australia could possibly face.

“It’s a very complicated, fast-arriving threat,” he said.

A network of seismic monitors, sea level gauges and deep ocean buoys deliver information to the scientists at both the BoM and Geoscience Australia.

“Then our people, forecasters on the desk, look at scenarios from pre-run computer models to look at where the threat is likely to be,” said Mr Bailey.

“Then they start talking to emergency managers around the country about what is likely to happen, and start generating the warning bulletins.”

They have less than 25 minutes to analyse the incoming information and disseminate the warnings.

The system is a vast improvement on what was in place a decade ago when hundreds of thousands of people were killed in a tsunami on Boxing Day 2004.

“It was a case of something’s coming, we don’t know how big, but we’ve got a rough idea of when,” said Mr Bailey.

“Now, with our computer modelling and forecasting and observations, we can try and make those warnings a little bit more useful.” 

However, the behaviour of a tsunami is still difficult to predict. “We still don’t know, because there’s such a complicated coastline…what the waves will actually do.”

International effort

The IOWAVE14 simulations were held across two days, 9 -10 September, 2014.

The first day involved a scenario where a major earthquake south of Java, Indonesia generated a tsunami.

In Australia the virtual tsunami generated Land Threat warnings in Western Australia, Cocos and Christmas Islands and Australia’s Casey and Davis bases in Antarctica.

Government agencies used the opportunity to test their ability to respond to a major, fast moving emergency situation.

For example, the ABC had to work out how it was going to keep communities informed of the threat while simultaneously evacuating staff from its local coastal offices.

In Madagascar and Mauritius authorities went as far as evacuating small communities as part of the exercise.

Mr Bailey said the simulations tested the Indian Ocean Tsunami Warning and Mitigation System under a “worst case scenario”.

“We test what happens here, what our forecasters do, our communication links with emergency services.”

The simulations are held every two years.

– Weatherzone/ABC