Australia's front-line defence
5 July 2011
If memories were fading of the devastation wrought by the 2004 Indian Ocean tsunami, Japan's Tohoku earthquake on 11 March served up a shocking reminder of the deadly force of earthquake-generated tsunamis – and our own continuing vulnerability on the edge of the Pacific Ocean's 'Ring of Fire'.
Within minutes of the Tohoku quake, an extensive regional network of seismic monitoring stations, coastal sea-level gauges and deep-ocean detection buoys had sprung into action, enabling the Joint Australian Tsunami Warning Centre to issue a No Threat Tsunami Bulletin for Australia in less than 30 minutes.
The system proves the lifesaving potential of a $70 million investment by the Australian Government following the 2004 tsunami, to establish a world-class warning system combining the expertise of Geoscience Australia, the Bureau of Meteorology, and their domestic and international partners.
Today, the Centre, operating between Canberra and Melbourne, is the sole authority for issuing tsunami warnings and advice for Australia and its offshore territories.
Seismologists from Geoscience Australia receive real-time data from a network of over 170 seismic stations in Australia and across the Indian and Pacific Ocean regions. If an undersea earthquake occurs with a magnitude above 6.5 Mw and at a depth of less than 100 metres, a comprehensive monitoring system is activated involving the Bureau's extensive sea-level instrumentation network and the very latest tsunami-impact computer modelling.
The two agencies use the information to determine whether a tsunami has been generated, where and when it will reach Australia's shores and the likely impact on marine and coastal areas.
Through the Bureau's media and emergency contacts, the Centre issues immediate and continuous warnings to the public, emergency services, police, and maritime authorities. Public updates are also uploaded to the Bureau's website, and an online 'threat map' is activated to show areas at risk, levels of threat, and relevant warnings.