Australia’s tsunami warning system will be expanded late this year, so Indian Ocean tsunami information can be issued to other countries in the region, Clare Atkinson reports.
The completed Australian warning system began in late 2008, with the capability for full tsunami warnings, categorised down to state level and even coastal zones within each state.
It now claims to have one of the most sophisticated warnings systems in the world.
Currently the Australian centre only issues warnings for Australia and its territories, such as Christmas and the Cocos Islands in the Indian Ocean, Lord Howe and Norfolk Islands in the Pacific, and Australia’s Antarctic territories.
The Joint Australian Tsunami Warning Centre is operated by the Bureau of Meteorology and Geoscience Australia, with offices in Melbourne and Canberra.
The first step in issuing tsunami warnings involves GeoScience Australia.
Its role is to detect earthquakes that have the potential to cause a tsunami in the Indian Ocean, the Pacific Ocean and the Southern Ocean.
It has to advise the weather bureau whether there is tsunami potential within fifteen minutes of an earthquake occurring.
But as Dr Barry Drummond from GeoScience Australia explains, this can be difficult.
“There are some tricks in that because, for example, you have to wait for the seismic waves to travel through the earth to enough seismograph stations so you can categorise it properly,” Drummond he told SBS.
“Usually we can get a location within five to six minutes. Getting a magnitude is really important but the problem there is a really, really big earthquake can take ten minutes to rupture so you’re trying to get a magnitude in ten to eleven minutes when the earthquake is almost still rupturing.”
The weather bureau then uses equipment that monitors sea levels to confirm the existence of a tsunami and estimates its likely impact using tsunami computer models.
It’s also the bureau’s responsibility to issue warnings to emergency services, local councils, port authorities, police and the media.
The aim is to have messages out to emergency managers at least 90 minutes before a tsunami hits the Australian coastline.
Currently there is no system to send warnings via text message to the general public as has been done with fire warnings in Australia, but the tsunami centre is considering the idea.
One of the most crucial parts of the tsunami warning system is preparing and planning for a possible event.
“So that is preparing along the coastlines for communities to know what to do should a tsunami warning be issued,” Dr Drummond explains.
“The third part of the triangle Emergency Management Australia and the work that we do with them, working with the states and territories, is to work out what the effects will be of tsunamis on those coastal communities so the states and territories can prepare their plans should a tsunami be on its way.”