Tsunamis

The Blue Tsunami Evacuation Zone includes beaches, lagoons and river mouths as well as low-lying coastal land that could be flooded by a tsunami. How far inland the evacuation zone goes is based on scientific modelling of large tsunamis coming from close to the New Zealand coast, as well as from across the Pacific Ocean.

You should leave this zone immediately if you:

• feel a long or strong earthquake, OR
• see a sudden rise or fall in sea level, OR
• hear loud or unusual noises from the sea (like a jet plain or train), OR
• are told to evacuate by Civil Defence.

Stay out of this zone until you are told it is safe to go back.

Not in the Blue Tsunami Evacuation Zone?

If you are not in the Blue Tsunami Evacuation Zone you:

• don’t need to evacuate after a long or strong earthquake,
• don’t need to evacuate during an official warning from Civil Defence,
• may wish to open your home to family or friends who need to evacuate.

A long earthquake is when the shaking lasts for more than one minute. The bigger the earthquake magnitude, the longer the shaking. If the earthquake lasts for longer than a minute, then it's a big one somewhere, even if the shaking is moderate or mild in Waimate, and it may have created a tsunami.

A strong earthquake is when the shaking is so strong it is hard to stand up, furniture starts moving around and things fall over.

You will only get an official tsunami warning if there is time to issue one.

If a tsunami is created close to shore, there will not be time to give an official warning. This is why you must move out of the Blue Tsunami Evacuation Zone immediately after a long or strong earthquake – do not wait for an official warning, siren, emergency mobile alert, or for someone to tell you to go.

If a tsunami is coming from further away, an official advisory or warning will be issued, and you will be told which areas to evacuate or stay out of. You may not need to evacuate the whole zone, you may just need to stay out of the sea, lagoons and river mouths and off beaches. Advisories or warnings will be broadcast on television, radio, social media and emergency mobile alerts. Emergency services might go through the evacuation zone to get people out if there is time. You can do your bit by passing information on to family, friends and neighbours.

If you are told to evacuate in an official warning you may have up to several hours to leave the Blue Tsunami Evacuation Zone.

Things you need to consider:

• Take valuables and important documents, as well as clothes, toiletries, medicines and supplies for children and pets. Know where these things are if you need to pack them up quickly. Depending on the impact of the tsunami you could be away from your home for hours or days.
• Where will you go? If possible, stay with family or friends outside the evacuation zone. A Civil Defence Centre will be opened for people who need emergency accommodation, but this can take some time.
• Secure your home as you normally would when leaving for an extended period.
• Check on your neighbours and vulnerable people you know of to see if they need help – Police and Civil Defence resources will be stretched in an evacuation.
• What is the best route for you to take? In an official evacuation, there will likely be traffic management in place, but you need to have thought about this in advance.
• Take your pets with you if you can – they are your responsibility. Civil Defence Centres generally will not accept pets, apart from service animals, so you need to have somewhere you can take your pet. Some Civil Defence Centres will have arrangements for pets nearby, so make sure you take pet food, bowls, leash, muzzle and kennel if possible.
• Residents will be allowed into evacuation zones to pick up family and pets if there is time, provided it is safe to do so before the threat becomes imminent.
• If you are farming along the coast, evacuate your whānau/family and staff first. If you have time, move livestock to higher ground.

Tsunamis can travel a surprising way up rivers – this is called a bore. Even small tsunamis can create strong currents and surges in river mouths. The tsunami evacuation zone goes further inland up riverbeds to take this into account.

If you are not in a tsunami evacuation zone then flooding is not expected even in a very large tsunami and you don’t need to evacuate. We appreciate that you may still wish to evacuate, but please be mindful of keeping the roads clear for others who do need to evacuate from the Blue Tsunami Evacuation Zone.

Civil Defence won’t be able to personally help you evacuate if you need to in a tsunami. This is why it’s important to have an evacuation plan ready for you and your household. If possible, make a plan with family or friends who live outside the tsunami evacuation zones to stay with them if you need to evacuate.

For more information and resources on tsunamis visit:

Environment Canterbury’s tsunami pages https://www.ecan.govt.nz/your-region/your-environment/natural-hazards/tsunamis/

Canterbury Civil Defence Emergency Management Group’s tsunami page https://www.cdemcanterbury.govt.nz/hazards/tsunamis/