Tsunami evacuation zones and warnings

Tsunami evacuation zones

Tsunami evacuation zones are areas we recommend people evacuate or stay out of if they feel a long (more than a minute) or strong (hard to stand up) earthquake, or in an official tsunami warning.

Canterbury has a blue tsunami evacuation zone. The blue zone identifies areas that may be affected by a tsunami and where people may need to evacuate during the threat of a tsunami.

Search your address or location in the map below to find out whether you are in it.

View full tsunami evacuation zone map

You can find tsunami evacuation zones and what they mean for other parts of New Zealand on the National Tsunami Evacuation Zone Map. 

Tsunami warnings

Know the natural warning signs

If a tsunami is coming from close to our shores, there may not be time for an official warning or an emergency mobile alert. The earthquake is your warning.

If you:

Feel an earthquake that shakes for longer than a minute, OR
Feel an earthquake that is so strong it is hard to stand up and things are being knocked over, OR
See the sea behaving strangely or hear the sea making loud, roaring noises

Then move inland or to higher ground, out of the blue tsunami evacuation zone, as soon as the shaking stops.

Do not wait for an official warning, an emergency mobile alert on your phone, sirens, or for someone to tell you to leave.

In urban areas, walk or cycle if you can, so you don’t get stuck in traffic or blocked by damaged roads and bridges. Be aware of potential rockfalls in hilly areas.

Stay away until you are told it is safe to return – the first tsunami wave may not be the largest and waves can continue for many hours.

If you are not in the blue tsunami evacuation zone you do not need to evacuate after a long or strong earthquake. Evacuating if you don’t need to can cause more traffic jams, making it harder for those in the blue zone to get out.

Official warnings

If a tsunami is coming from further away, from the Pacific Islands or across the Pacific Ocean, you won’t feel the earthquake but there will be time to issue an official warning. You may receive this as an emergency mobile alert on your phone, through social media, radio or television, or through a siren where they are installed.

An official warning will tell you which areas to evacuate or stay out of. You may not need to evacuate the whole blue tsunami evacuation zone, you may just need to stay out of the sea, lagoons, estuaries, river mouths and off beaches.

You can also check the Canterbury Civil Defence Emergency Management Group website and social media accounts for more information in the event of an emergency.

Emergency Mobile Alerts

Emergency Mobile Alerts (EMAs) are messages sent by emergency agencies to capable mobile phones. An EMA can be targeted to a specific area and will only be sent when there is a serious threat to life, health or property.

If you are in the blue tsunami evacuation zone you should evacuate immediately after a long or strong earthquake and not wait for an EMA. If a tsunami has been created close by there may not be time to send one.
If a tsunami is likely to flood land and there is time to do so, the National Emergency Management Agency (NEMA) will send an EMA to the areas under threat. It will tell people to either evacuate immediately or to prepare to evacuate if the first waves aren’t expected for several hours. The Canterbury Civil Defence Emergency Management Group will send a follow-up EMA to the areas under threat with more detailed local evacuation information.

Immediately follow the advice of any emergency warning. Do not wait for more messages before you act.

You can check if your phone can receive EMAs on the Get Ready website.

Sirens

If you are in the blue tsunami evacuation zone and feel a long or strong earthquake, do not wait for a tsunami siren to sound. Evacuate as soon as the shaking stops.

Sirens can be useful in some circumstances but are generally not recommended, as people tend to wait until they hear the siren before they evacuate instead of evacuating on the natural warning of a long or strong earthquake.

This can put people at greater risk as there will not be time to sound sirens if a tsunami is coming from nearby.

If you hear tsunami sirens, where they are installed, follow the instructions in the siren message.

If it is a tone siren turn on the radio or check your local council website or social media to see if you need to evacuate.

You can find more information about tsunami warning systems in your area through your local city or district council.

Where to get information in a tsunami evacuation

During a tsunami evacuation, you will be able to get information from:

The Canterbury Civil Defence Emergency Management Group website and social media accounts
Your local council website and social media accounts

TV and local radio stations.

Learn more about the blue tsunami evacuation zone

The blue tsunami evacuation zone is based on modelled flooding from ‘worst case’ tsunamis from several different locations, both close to our shores and across the Pacific Ocean. You can see the modelled tsunami flooding in our Canterbury Tsunami Model Results webapp. The evacuation zone covers small tsunamis that may not flood much, if any, land as well as rare, large tsunamis that could flood a lot of land. This follows national guidance from the National Emergency Management Agency.

In drawing the evacuation zone we also consider:

areas that might not be flooded but could be cut off or isolated by debris-laden tsunami water,
how easy the zone is to communicate – we will often move the zone boundary slightly inland to run along a road or other easily identifiable landmark,
the risks of evacuating too many people, such as traffic jams and accidents and delays for people closer to the coast,
the location of parks, schools, early childhood centres, aged care facilities and other facilities for vulnerable people.

Tsunami evacuation zones and warnings