On 14 October 2009 Australia participated in an international tsunami warning system testing exercise in countries surrounding the Indian Ocean. The exercise scenario revisits the Indian Ocean Tsunami (IOT) of 26 December 2004.
The exercise tested the Interim Advisory Service (IAS), provided by the Pacific Tsunami Warning Centre in Hawaii and the Japan Meteorological Agency in Tokyo, and also the procedures and lines of communication between the IAS, National Tsunami Warning Centres and National Disaster Management Organisations in response to a potentially destructive tsunami in the Indian Ocean Region.
Australia has an independent national capability for tsunami warnings that is not reliant on the Interim Advisory Service. However, Australia participated in this exercise to test the warning capabilities of the Joint Australian Tsunami Warning Centre (JATWC) and communications with relevant Federal, State and Territory emergency services.
The exercise was conducted and coordinated by the Intergovernmental Coordination Group for the Indian Ocean Tsunami Warning & Mitigation System which was established by UNESCO's Intergovernmental Oceanographic Commission after the IOT 2004. The exercise scenario was the IOT 2004 event revisited, with the earthquake occurring 0100Z UTC 14 October 2009.
As occurred during 2004, the simulated impacts on Australia were relatively minor compared to other countries. However, a "Tsunami Warning for the Marine Environment" was simulated for significant parts of the coast, utilising the new capabilities of the Joint Australian Tsunami Warning Centre (JATWC). This level of threat would normally indicate the potential for dangerous waves and currents in the marine environment only. On 26 December 2004, 35 people in Australia were rescued on beaches after being caught in dangerous rips.
The exercise was conducted on United Nations International Disaster Reduction Day, when nations across the globe focus on the goal of reducing the impact of natural disaster on vulnerable communities.
JATWC computer modelled forecast of wave behaviour of the tsunami generated by simulated earthquake for Tsunami Exercise Indian Ocean Wave 09
A Tsunami Watch is first issued by the Joint Australian Tsunami Warning Centre (JATWC) for Australia when there is the potential risk of a tsunami being generated in the region by an undersea earthquake. The Tsunami Watch remains in place while the level of threat is assessed by the JATWC. No community response is required.
The watch will be cancelled if the tsunami did not eventuate, or one of two warnings will be issued for specified parts of the coastline if a tsunami is verified by Australia's tsunami detection system of deep ocean buoys and coastal sea level stations, either:
a) Tsunami Warning for the Marine Environment: indicating a threat of dangerous ocean surges and rips in the marine environment. People will be advised to get out of the water, move away from beaches and the waterfront, and secure boats or leave them in deep water; or:
b) Tsunami Warning of Land Inundation: indicating a threat of dangerous waves and possible land inundation. People will be strongly advised to go to higher ground, 10m above normal sea level, or if possible move at least one kilometre away from all beaches and the water's edge of harbours and coastal estuaries.