What Is a Tsunami and How Should You Respond in Victoria?

A tsunami is a series of ocean waves caused by a large disturbance of the sea floor or the water above it — most often an undersea earthquake, but also undersea volcanic eruptions, landslides, or meteorite impacts. In Victoria, tsunami is one of the emergencies VICSES (Victoria State Emergency Service) plans and responds for, alongside flood, storm, earthquake and landslide. If you are in Victoria and a tsunami warning is issued, your priority is to move away from the coast and low-lying areas, follow official warnings from VicEmergency and the Bureau of Meteorology (BOM), and only call 132 500 for VICSES assistance — not for life-threatening emergencies, which go to Triple Zero (000).

How a tsunami forms and how it behaves

A tsunami is not a single wave. It arrives as a series of waves, and the first one is often not the largest. Key characteristics:

• Trigger: Usually a shallow, large undersea earthquake that displaces a column of water. Landslides and volcanic activity can also generate tsunamis.
• Speed and height: In deep ocean, tsunami waves can travel at jet-aircraft speed but with small height. As they reach shallower coastal water, they slow and grow.
• Timing between waves: Waves can arrive minutes to hours apart, so the danger can persist long after the first impact.
• Local vs. distant source: A tsunami generated close to shore may arrive within minutes, leaving little time for official warnings. A distant-source tsunami gives more warning time.

Is tsunami a real risk in Victoria?

VICSES treats tsunami as one of the emergencies it plans for across Victoria, and the agency publishes tsunami guidance under its "Plan and stay safe" section. Victoria's exposure is mainly through its coastline and low-lying coastal areas, and the risk can come from either distant or nearby undersea events. Because tsunami is listed alongside flood, storm, earthquake and landslide as a VICSES responsibility, the practical takeaway is that coastal communities should include tsunami in their emergency planning rather than assume it cannot happen.

For local risk detail, VICSES directs people to its Local Flood Guides for understanding local flood risk, and its broader emergency pages for tsunami. Use the tsunami page on the VICSES site as your starting point for official Victorian guidance.

Warning signs you should act on

You may have little or no official warning, especially for a local-source tsunami. Treat any of these as a cue to move inland and to higher ground:

• Strong or prolonged shaking from an earthquake near the coast.
• A sudden rise or fall in sea level, or the sea receding unusually far and exposing the sea floor.
• A loud roar from the ocean, like a train or aircraft.
• An official tsunami warning from VicEmergency or BOM.

Do not go to the beach to watch. Tsunami waves and strong currents are dangerous, and the first wave may not be the biggest.

What to do before, during and after

Before

• Know your route: Identify how you would get inland and to higher ground from where you live, work or holiday. VICSES stresses planning for emergencies at home, at work, at school and on holidays.
• Create an emergency plan: VICSES provides a "Create an emergency plan" resource so households and workplaces can decide in advance what they will do.
• Understand warnings: Learn how VicEmergency and BOM warnings are issued and what they mean, so you can act quickly.
• Check local guides: Review the Local Flood Guides and VICSES tsunami information for your area's specific risk.

During

• Move away from the coast and low-lying areas immediately — go inland and to higher ground.
• Follow official instructions from VicEmergency and BOM. If told to evacuate, do so.
• Stay out of the water and off beaches, and keep away from harbours, rivers and estuaries, where tsunami currents can be strong.
• Do not return until authorities say it is safe; multiple waves can arrive over an extended period.

After

• Wait for the all-clear from official sources before returning to coastal areas.
• Avoid damaged areas and debris, and stay clear of floodwater and contaminated water.
• Check on others if it is safe to do so, and follow VICSES recovery guidance after an emergency.
• Report damage or request assistance through the correct channels (see below).

Who to call and where to get warnings

VICSES lists these contact points together: VicEmergency warnings, BOM weather and warnings, flood and storm emergencies on 132 500, and life-threatening emergencies on Triple Zero (000). Note that 132 500 is for VICSES assistance — it is not the number for a life-threatening emergency.

Practical checklist for coastal Victorians

• [ ] Confirm whether you live, work or holiday in a tsunami-risk coastal or low-lying area.
• [ ] Read the VICSES tsunami page and your Local Flood Guide.
• [ ] Write an emergency plan using the VICSES "Create an emergency plan" resource.
• [ ] Identify your inland/higher-ground route and a meeting point.
• [ ] Set up VicEmergency and BOM as your warning sources.
• [ ] Know the difference: 132 500 for VICSES help, 000 for life-threatening emergencies.

The core message is simple: tsunami is a recognised emergency in Victoria, warnings may be short, and the safe response is to move inland and to higher ground while following official VicEmergency and BOM advice.