Learn more about Tsunami

Tsunami Risk

Marine and Immediate Foreshore Threat

Warning of potentially dangerous rips, waves and strong ocean currents in the marine environment and the possibility of only some localised overflow onto the immediate foreshore.

Land Inundation Threat

Warning for low-lying coastal areas of major land inundation, and flooding, dangerous rips, waves and strong ocean currents in the marine environment.

Tsunami poses the following key risks:

Risk to life:

There is a significant risk of drowning during tsunami with either marine and land inundation threat.  This is due to the potentially dangerous rips, waves, water born debris and strong ocean currents.

  • During a Marine and Immediate Foreshore threat, the risk to life includes drowning,
  • During land inundation tsunami inundation is widespread and extends to areas not normally submerged by water.  Tsunami waves can run up well beyond the high tide mark, in extreme cases up to a kilometre inland or up to 10 metres above sea level. Tsunami can also extend into harbours, rivers and estuaries.  This is why tsunami safety advice for a tsunami with land inundation threat states that you should move away from low lying coastal areas, harbours and estuaries as soon as a Tsunami Warning is issued
  • Tsunami are a series of multiple waves that can last several hours. Tsunami are fast moving and very powerful and the first wave may not always be the biggest. Therefore it is important not to return to low lying coastal areas until advised by emergency services that it is safe to do so

Risk of property damage

  • Boats and other vessels can be at risk from damage due to tsunami.  Boats are most at-risk in shallow water where the surge associated with tsunami waves can capsize vessels, push them into other boats The Saxon, sank at its mooring in Geralton in 2004 due to tsunamiand obstacles, or wash debris into the boat. The skipper and any passengers are still at risk if they are still on-board or within the tsunami impact area when the tsunami arrives
  • Marinas, moorings, ports and other marine based infrastructure can be at risk of damage by the sudden surge of water caused by tsunami. Much of this damage is unavoidable and the best advice is to securely tether boats to moorings. You should always prioritise life over property damage by leaving the area as soon as a Tsunami Warning is issued, and ensuring you are outside the area at-risk well before the first wave arrives
  • Homes, businesses and other property such as caravans and cars situated in low-lying coastal areas can also be affected by tsunami.  Much of the damage to this property will be caused by land based tsunami and in these rare cases is often unavoidable.  You should prioritise your life and the lives of others above any damage to property.  However planning for natural disasters may assist you to make good early decisions that could potentially help you mitigate some of this damage.