Tsunami

All of Auckland's coastline is vulnerable to tsunami.

What is a tsunami?

A tsunami is a series of powerful waves caused by large, sudden disturbances on or near the ocean floor. Tsunami can hit the coast with massive force, creating strong currents and can travel considerable distances inland across low-lying areas, flooding coastlines. They are most commonly caused by earthquakes but may also be caused by underwater volcanic eruptions or landslides. New Zealand’s position on the edge of the Pacific Ring of Fire makes its exposure to tsunami hazards high.

Tsunami may cause injuries or loss of life, if people do not evacuate tsunami risk zones. They can cause widespread property damage, lifeline utility disruption and significantly impact our communities and environment.

When do they occur?

A tsunami can occur at any time. In deep water, tsunami waves are small and barely noticeable, but when tsunami enter shallow water they increase in height. Some tsunami can be very large and cause widespread destruction, others can be small but still dangerous to those near or in coastal waters.

It is important to remember that not all earthquakes will generate a tsunami, and that New Zealand can be affected by tsunami generated far from our coast, or from nearby. Even nearby, the cause of the tsunami - such as an earthquake on the seabed - may not be felt on land. If you are at the coast and feel a strong earthquake that makes it hard to stand up, or a weak rolling earthquake that lasts a minute or more, you may be at risk from a tsunami.

Earthquakes are not the only sign of an impending tsunami. Natural warning signs such as unusual sea behaviour including sudden rising or falling sea levels or unusual sounds at the coast may indicate a tsunami threat.

Tsunami Warning and Auckland region tsunami siren network

In the event of a tsunami emergency, an Emergency Mobile Alert (EMA) will be triggered. Your phone will receive a message which will tell you what the emergency is and what to do. Besides Emergency Mobile Alert, we will also get the messages out through broadcast on radio, television, news media and social media platforms.

The Auckland region also has a siren network that will be triggered in the event of a tsunami threat.

Update Tues 5th Sep 2023: The Auckland Civil Defence and Emergency Management Committee Committee has voted to decommission the aging and compromised Meerkat tsunami siren network. This decommissioning decision only relates to the older siren network, and not to the two new sirens installed in 2020 in Orewa, which are working as expected and have not experienced any vandalism or thefts.

Learn more about our tsunami warning channels

HOW TO PREPARE

What do I need to do to be ready?

Before

Check the Auckland’s Hazards Viewer to find out if you live, work or play in an area at risk of tsunami.
Learn and practice your tsunami evacuation route.
Organise a tsunami walk (hīkoi) for your household, organisation or community.

During

If you’re on the coast and you…

Feel a strong earthquake that makes it hard to stand up or a weak rolling earthquake that lasts a minute or more,
See a sudden rise or fall in sea level,
Hear loud and unusual noises from the sea…

Don’t wait for an official warning…

Go immediately to the nearest high ground or as far inland as you can, take the route that is quickest for you. Do not stay at home. If possible, run, walk or cycle when evacuating from a tsunami - you don’t want to get stuck in traffic in a tsunami zone.
Don’t go to the shore and watch.
Listen to the radio and follow the instructions of emergency services.
Stay away from exposed areas until the official all-clear is given by authorities and emergency services.
Take your emergency getaway bag and pets with you if you can.

After

Stay tuned to a radio station for updated emergency information. The tsunami may have damaged roads, bridges, or other places that may be unsafe.
Check yourself for injuries and get first aid if necessary before helping injured or trapped persons.
If someone needs to be rescued, call the emergency services with the right equipment to help. Many people have been killed or injured trying to rescue others in flooded areas.
Help people who require special assistance – infants, elderly people, those without transportation, families who may need additional help in an emergency.
Know there may be more than one wave and it may not be safe to go home for 24 hours or more; the waves that follow the first may also be bigger.
Don’t return to the evacuation zones until emergency services and authorities have given the all-clear.
Don’t go sightseeing.
Use extreme caution when going into homes or buildings as they may be damaged.
Report broken utility lines to appropriate authorities.
Contact your insurance company if your property is damaged or, if you rent, contact your landlord.