Joint Australian Tsunami Warning Centre
Roles in the JATWC
Geoscience Australia's role in the JATWC is two-fold:
- to detect earthquakes that have the potential to generate tsunami that can impact Australia's coastline, and advise the Bureau of Meteorology of this potential within 10 minutes of the earthquake occurring
- to undertake tsunami risk studies to assist local and state organisations in planning for tsunami events.
The Bureau of Meteorology's role is also two-fold:
- to use its network of sea level monitoring equipment, including coastal tide gauges and tsunameters (deep ocean tsunami sensors), and tsunami propagation models to confirm the existence of a tsunami and estimate its likely impact at the Australian coast
- to issue the relevant tsunami warnings and bulletins for Australia and external territories as required.
What does the JATWC do?
Geoscience Australia receives real-time data from over 60 seismic stations in Australia and more than 130 international seismic stations. The seismic information is automatically analysed by Geoscience Australia's seismic monitoring and analysis systems that form part of the 24 hours a day, seven days a week operations centre. When an earthquake occurs, this system automatically computes preliminary information on the earthquake's origin time (time at which the earthquake happened), location, depth and magnitude. The Duty Seismologist assesses this information and then calculates a moment magnitude, Mwp, (similar to a Richter magnitude) to assist in determining the potential for the earthquake to cause a tsunami. If Duty Seismologist considers that the earthquake has the potential to generate a tsunami that may impact Australia, the seismologist sends the information to the JATWC office in the Bureau of Meteorology in Melbourne via a dedicated data link. This process is completed within 10 minutes of the earthquake's origin time.
The JATWC also receives data from the Bureau of Meteorology's sea level observations and other international sea level stations. These instruments provide real-time sea level observations that can verify whether an earthquake has generated a tsunami and, if so, monitor its path. The data are provided by coastal sea level stations and deep ocean tsunami detection sensors. Equipped with these sea level data and the Bureau of Meteorology's tsunami modeling, specially trained JATWC staff then issue a warning that is in keeping with the determined threat level. These warnings identify affected coastal regions, initial tsunami arrival times and whether the tsunami threat is to land or marine areas. Upon receiving the earthquake alert from Geoscience Australia, the Bureau of Meteorology issues a tsunami bulletin within 10 minutes of receiving the alert. The JATWC is thus able to issue tsunami bulletins within 20 minutes of the origin time of the earthquake.
The Bureau of Meteorology issues advice and warnings on identified tsunami threat to emergency management agencies and the public using procedures similar to those used for warnings of other severe weather or hazardous events. Procedures include:
- distributing tsunami bulletins and warnings to the media, key agencies such as the state and territory emergency services, local councils, port authorities, police and the public
- working with media organisations across Australia to inform the public in the case of a tsunami event
- maintaining tsunami bulletin and warning distribution lists at each of the Bureau of Meteorology's state and territory Regional Forecasting Centres. These distribution lists are used for both national JATWC bulletins and regional warnings. The bulletin and warning messages are also automatically uploaded to the JATWC website.
The JATWC is also part of a network of international tsunami watch centres that cooperate under arrangements coordinated by the UN's Intergovernmental Oceanographic Commission (IOC) within UNESCO.