About Tsunami
A tsunami is a series of powerful waves primarily caused by a large earthquake under the seafloor. Tsunami can also be triggered by landslides, undersea volcanic eruptions, and meteorite impacts. These sudden disturbances can displace water and generate large waves that can travel hundreds of kilometers, eventually reaching land.
The Bay of Plenty is exposed to three tsunami sources: local, regional, and distant. Distant-source tsunamis, triggered by large offshore earthquakes far from New Zealand (such as off South America), may reach the Bay of Plenty coast within 12–15 hours. Local and regional tsunamis can be caused by landslides, offshore volcanoes such as Tūhua (Mayor Island) and Whakaari (White Island), or earthquakes along the Tonga–Kermadec–Hikurangi Trench. Local-source tsunami waves could reach the Bay of Plenty within minutes, leaving little or no time for an official warning to be issued. That’s why it’s important to recognise the natural warning signs - if an earthquake is long or strong, get gone.
Do not wait for official warnings
Are you prepared for a tsunami?
Know if you are in a tsunami evacuation zone: Familiarise yourself with your local tsunami risk. Know if you work, study, play, or live in a tsunami evacuation zone by looking at your local tsunami maps.
Plan your evacuation route: Find the best evacuation routes for you and your whānau, and where your nearest safe assembly area is if you’re in a tsunami evacuation zone. Sign up for the annual Shake Out earthquake drill and tsunami hīkoi (evacuation) to practice it together.
Know the natural warnings signs: For a local-source tsunami which can arrive in minutes, there is not enough time for an official warning to be issued. It is important to recognise the natural warning signs and act quickly. Remember, Long or Strong, Get Gone: if you are near the coast and experience any of the following:
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 water level.
Hear loud and unusual noises from the water.
Move immediately to the nearest high ground or as far inland as you can, out of tsunami evacuation zones.
Felt an earthquake that was Long or Strong? Get Gone and evacuate if:
You are near the coast or in a known tsunami evacuation zone
Feel a strong earthquake that makes it hard to stand up, or a weak rolling earthquake that lasts a minute or more
Notice any other natural warning signs such as a sudden rise or fall in sea level or loud and unusual sounds coming from the water
Get a tsunami warning via Emergency Mobile Alert or any other official channel
Move immediately to the nearest high ground or as far inland as you can, out of tsunami evacuation zones. Walk, run or cycle, if you can. This reduces the chance of getting stuck due to damaged roads or traffic congestion.
Do not go down to the shore to watch the waves. The first wave may not be the largest, and waves may keep coming for many hours.
Do not re-enter tsunami evacuation zones until an official all-clear message is given by Civil Defence Emergency Management.
Wait for the all-clear. Do not re-enter tsunami evacuation zones until officials have given the all-clear to say it’s safe in case more tsunami risks are identified.
Avoid hazardous areas. Keep clear from the coast, tidal estuaries, rivers, and streams for at least 24 hours after any tsunami or tsunami warning. Strong and unusual currents are likely to occur after a tsunami.
Act with extreme caution around floodwaters. Floodwater is dangerous, and may contain debris, and other hazardous material. Treat all floodwater as contaminated. Never walk, swim, drive, or play in floodwater.
Remember the first wave may not be the biggest, and waves may keep coming for many hours, so don’t go sightseeing. Stay away from at risk areas until the all-clear is given.
