Changes to tsunami evacuation maps for Auckland

Publish Date : 01 Feb 2024
Medlands Beach Aotea Great Barrier Island. (file photo, not taken during a tsunami)

New modelling shows the area of Tāmaki Makaurau at risk from damaging tsunami waves is less than previously expected. Auckland Emergency Management has updated and simplified the region’s tsunami evacuation maps to reflect this change and make them easier to understand.

John Cranfield, Auckland Emergency Management’s Head of Operations encourages Aucklanders to view the updated evacuation maps through Auckland’s Hazard Viewer to see if they live, work or play in a tsunami evacuation zone.

“Our new tsunami wave modelling is more accurate and indicates the tsunami risk for much of the Auckland coastline to be lower than previously expected.
“Aucklanders should check out the Hazard Viewer to help them become familiar with areas predicted to be flooded during a tsunami, as part of being prepared for an emergency.”

The new mapping uses modelled earthquakes on real fault lines around the Pacific to replicate how tsunami waves are generated and track across the ocean and to our coastline. The modelling takes into account how islands influence the path of tsunami waves, as well as how landforms on the coast and the shape of the seafloor influence the way tsunami waves behave.

Mr Cranfield says the new maps are also simpler to understand.

“The new maps use a two-colour system. The red zone shows the area needing to be evacuated in a shore and marine tsunami threat, when strong and unusual currents and dangerous surges at the shore are expected. The yellow zone shows the area needing to be evacuated where there is a land tsunami threat, where tsunami flooding is expected to affect inland areas.”

The new maps cover the entire Auckland coastline including the Hauraki Gulf Islands and Aotea Great Barrier Island.

Councillor Sharon Stewart, Auckland Council’s Civil Defence and Emergency Management Committee chairperson says it’s pleasing that new evacuation maps show fewer areas at-risk from tsunami flooding but says Aucklanders should still be alert to the risk of tsunami threats.

“The new modelling suggests fewer of our coastal communities are expected to be impacted during damaging tsunami in Tāmaki Makaurau. Particularly the areas surrounding the inner Manukau, Kaipara and Waitematā harbours and on the west coast beaches, where impacts are now expected to be confined to shore and marine areas.

“However, areas more exposed to the Pacific Ocean like Aotea Great Barrier Island and Auckland’s north-eastern coastal communities are still at risk of large tsunami, as is anyone that enjoys the beaches and marine areas of the region. People need to remain prepared to move quickly in a tsunami emergency.”

What are the official tsunami alert channels in the event of a tsunami emergency?

Tsunami warnings are published on the National Emergency Management Agency’s website and social media pages. Tsunami warnings will also be broadcast on radio, television and news media, as well as on the Auckland Emergency Management website and social media pages. An emergency mobile alert (message to your mobile phone) may also be issued in the event of a dangerous tsunami threat.  

What are the natural warning signs for a tsunami?

If you are near a shore and experience any of the following, take action. Do not wait for official warnings. 

  • Feel a strong earthquake that makes it hard to stand or a long earthquake that lasts more than a minute
  • See a sudden rise or fall in sea level
  • Hear loud or unusual noises from the sea

Remember! If an earthquake is LONG or STRONG, GET GONE and move to higher ground. 

Be prepared

Prepare your household emergency plan and practice it so everyone knows what to do in an emergency and what you need to take if you are evacuating.  

Check the Auckland hazard viewer map.

Check the tsunami preparedness tips and what to do before, during and after a tsunami.  

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