Many areas of Christchurch and Banks Peninsula are at risk of tsunami.
You can prepare for a tsunami by checking your tsunami zone using our interactive map, getting your household ready and knowing the warning signs.
Remember, if it's long or strong, get gone.
A tsunami evacuation zone is an area that you may need to evacuate from if you feel a long rolling earthquake that lasts more than a minute, or a strong earthquake that makes it hard to stand up, or if there is an official tsunami warning. You may be asked to stay out of the evacuation zone for many hours.
There are three tsunami evacuation zones for Christchurch and Banks Peninsula.
Use the magnifying glass to find your property and see if you live in an evacuation zone.
Red evacuation zone
Orange evacuation zone
Yellow evacuation zone
Christchurch and Banks Peninsula boundary
Red evacuation zone: Long or strong, get gone
This is an area that is most likely to be affected by a tsunami. You can expect to evacuate the red zone several times in your lifetime.
You should leave this zone immediately, if:
- You experience a long or strong earthquake
- You see sudden sea-level changes or hear unusual noises coming from the sea
- You receive an official warning from Civil Defence Emergency Management
Official warnings may be given through an Emergency Mobile Alert to your phone, through the Christchurch City Council newsline page, on radio, television, or social media. If there is an announcement to evacuate the zone you are in, follow the instructions immediately. If you hear the tsunami warning sirens, check any of the above sources for further information.
Stay out of this zone until you are told by an official source that it’s safe to go back.
Orange evacuation zone: Long or strong, get gone
This is an area that is less likely to be affected by a tsunami but still possible in a large tsunami. You can expect to evacuate the orange zone a few times in your lifetime.
You should leave this zone immediately, if:
- You experience a long or strong earthquake
- You see sudden sea-level changes or hear unusual noises coming from the sea
- You receive an official warning from Civil Defence Emergency Management
Official warnings may be given through an Emergency Mobile Alert to your phone, through the Christchurch City Council newsline page, radio, television, or social media. If there is an announcement to evacuate the zone you are in, follow the instructions immediately.
If you hear the tsunami warning sirens, check any of the above sources for further information.
Stay out of this zone until you are told by an official source that it’s safe to go back.
Yellow evacuation zone
This is an area that is least unlikely to be affected by tsunami but still possible in a very large tsunami. It's unlikely you'll need to leave this zone in your lifetime. You should still leave this zone immediately if you receive an official warning from Civil Defence Emergency Management.
Official warnings may be given through an Emergency Mobile Alert to your phone, through the Christchurch City Council newsline page, radio, television, or social media. If there is an announcement to evacuate the zone you are in, follow the instructions immediately.
If you hear the tsunami warning sirens, check any of the above sources for further information.
Stay out of this zone until you are told by an official source that it’s safe to go back.
Note: In most other parts of New Zealand, yellow zones need to be evacuated in a long or strong earthquake. You should check local tsunami evacuation zones when spending time on the coast.
No zone
This area is outside the tsunami evacuation zones. If you’re in this area:
- You don’t need to evacuate in a long or strong earthquake
- You don’t need to evacuate during an official tsunami warning from Civil Defence Emergency Management
- You may wish to open your home to family or friends who need to evacuate from a tsunami evacuation zone.
The tsunami evacuation zones were determined by hazard scientists and emergency managers and reflect our best knowledge as at November 2020.
As research about earthquakes and tsunami risk continue, and further modelling work develops, it is possible that the zones could change. This page will contain the latest information.
It's important to have a plan for you and your whānau to follow in an emergency.
When a tsunami risk occurs you may be at home, school, work or out and about. Talk to everyone in your household about a safe place to go to outside of the tsunami evacuation zones. If you have friends or family that live outside of the evacuation zones, talk with them now about whether you can go to their place during an evacuation.
Use the resources at Get Ready(external link) to ensure everyone in your household knows where to evacuate to, how they will get there, what to take and how to stay informed.
In the event of a possible tsunami threat, warning signs and messages can come from several sources – natural and official.
Natural warnings
A natural warning may be the only warning for tsunami generated close to our shore. Natural warnings are:
- a rolling earthquake that lasts longer than a minute
- a strong earthquake that makes it hard to stand up
- unusual or sudden rise or fall in sea level
- unusual and loud noises coming from the sea – like a jet plane or a train
If you are in the red or orange evacuation zones you should evacuate immediately if you experience these warnings. Do not wait for an official warning.
Official warnings
Official warnings will normally be issued by Civil Defence Emergency Management and/or emergency services.
Official warnings will only be issued if there is enough time. The time it takes for a tsunami to reach our coastline depends on where it originates and how far it has to travel.
Official warnings may be given through an Emergency Mobile Alert to your phone, on ccc.govt.nz, radio, television, or social media. If there is an announcement to evacuate the zone you are in, follow the instructions immediately.
Emergency Mobile Alerts
Civil Defence use an Emergency Mobile Alert that is delivered to mobile phones located within a targeted area. If your phone is on, capable, and inside the targeted location, you should get the alerts. You don’t have to download an app or subscribe to a service.
Tsunami sirens
Tsunami sirens are installed along the Christchurch coastline. These could be activated for a distance source tsunami generated overseas (e.g across the Pacific Ocean) with more than three hours of warning time.
In some instances, if time permits, the sirens could also be sounded for a regional source tsunami generated in another area of New Zealand. This indicates a tsunami with one to three hours of warning time.
The sirens are not intended to warn you about a local source tsunami created close to our shore. A long or strong earthquake will be your only warning for this type of tsunami.
When the tsunami sirens sound for a tsunami warning, they will play a pre-recorded message to advise you what tsunami evacuation zones need to be evacuated.
|
Type of message |
Tsunami siren message |
Action required |
|---|---|---|
|
Evacuate Red and Orange |
[tone] [Attention. This is a tsunami warning. Evacuate the Red and Orange tsunami evacuation zones immediately.] |
Evacuate the Red and Orange tsunami evacuation zones immediately. Check official sources for further information once outside of the tsunami evacuation zones. |
|
Evacuate Red, Orange and Yellow |
[tone] [Attention. This is a tsunami warning. Evacuate the Red, Orange, Yellow tsunami evacuation zones immediately.] |
Evacuate the Red, Orange and Yellow tsunami evacuation zones immediately. Check official sources for further information once outside of the tsunami evacuation zones. |
|
Safe to return or All Clear |
[tone] [This is a civil defence all-clear message. Check official sources for more information.] |
The tsunami threat has now passed. Check official sources for information about when you can return home. |
|
Siren testing |
[tone] [This is a test of the tsunami warning sirens. Do not be alarmed. This is only a test.] |
No action is required. |
Primary tsunami evacuation routes are suggested routes to move out of tsunami evacuation zones.
- Harbour Road - Kainga Road - Marshlands Road (Kainga)
- Lower Styx Road - Marshlands Road (Styx)
- Beach Road - Mairehau Road (Northshore)
- Bowhill Road - Travis Road (North New Brighton)
- Hawke Street – Pages Road
- Towards city from Wainoni Road
- Bridge Street - Breezes Road (South New Brighton)
- Bridge Street - Dyers Road - Linwood Avenue (Southshore)
- Rocking Horse Road - Estuary Road - Bridge St (Southshore)
- Marine Parade - Bridge St (Southshore)
- Main Road - Ferry Road (Redcliffs)
- Wakefield Avenue - Evans Pass Road - Summit Road (Sumner)
- Ferry Road (Ferrymead)
- Bridle Path Road - Tunnel Road (Heathcote Valley)
How you'll stay informed
Information could change while you are evacuating, so make sure you have a way to stay up-to-date with official information, like a portable radio, or your mobile phone.
Official information will be available on:
- This website (ccc.govt.nz)
- Council's Newsline(external link) channel
- Council and Civil Defence social media channels
- RNZ National Radio – 101.7 FM or 675 AM
- The Hits – 97.7 FM or 96.5 FM
- Newstalk ZB – 100.1FM or 1098 AM
- More FM – 92.1 FM, 94.9FM or 99.1 FM
- Magic – 99.3 FM or 738 AM
- The Breeze – 94.5 FM
- Plains FM - 96.9FM
The nature of the landscape around Christchurch and Banks Peninsula means we are at risk from a range of different tsunami types whether they are local source, regional source or distant source.
Tsunami are created by underwater earthquakes, volcanic eruptions or landslides, and are made up of powerful waves or surges lasting for several hours or even days. Only the largest tsunami flood land; most tsunami are not big enough to flood land but can still cause strong and unpredictable currents and surges in the sea, which can be dangerous for people in the water, on beaches and at river mouths.
The first tsunami wave may not be the largest and waves can arrive for hours. So a tsunami warning can be in place for many hours.
The source of a tsunami can be local, regional or distant, depending on where it originates and how long it takes to travel to our coast.
| Type of tsunami | What you need to know |
|---|---|
| Local source tsunami |
Local-source tsunamis are those generated less than one hour’s travel time from Christchurch or Banks Peninsula. The main local-source tsunami risk for Christchurch and Banks Peninsula is a tsunami generated in the southern Hikurangi subduction zone. Modelling by GNS science and NIWA estimates a tsunami generated from the southern Hikurangi subduction zone (off the east coast of the North Island/Marlborough region) could reach Christchurch and Banks Peninsula in approximately one hour. Modelling of a magnitude 8.9 Hikurangi subduction zone earthquake estimates shaking could be felt for longer than one minute in Christchurch and Banks Peninsula. The shaking intensity would be dependent on the direction of the fault rupture but is likely to be between strong to heavily damaging Things to remember The earthquake is your warning. A local source tsunami will take less than one hour to reach the coast. It is unlikely there will be enough time to issue an official warning (including an Emergency Mobile Alert) for a local source tsunami. An earthquake that could cause a local source tsunami would be felt as a long (lasting more than one minute) or strong earthquake (making it hard to stand up). |
| Regional source tsunami |
Regional-source tsunamis are those generated within one to three hours travel time to the Christchurch and Banks Peninsula coast. There are two major regional tsunami sources that could impact Christchurch and Banks Peninsula. A tsunami from the Kermadec subduction zone (northeast of the North Island) could reach Christchurch and Banks Peninsula in approximately two hours. A tsunami from the Puysegur subduction zone (south of Fiordland; ) could reach Banks Peninsula in approximately three hours and Christchurch in approximately four hours. A Puysegur-generated tsunami is classed as a local tsunami threat for New Zealand (e.g. Southland and Fiordland) but would be classed as a regional threat to Christchurch and Banks Peninsula because it takes longer than one hour to reach us. A large magnitude >9.0 earthquake on these subduction zones will cause shaking that may last for more than one minute, but Christchurch and Banks Peninsula may experience mild to moderate shaking or not feel the earthquake at all. Things to remember There may be time to issue an official warning for a regional source tsunami (including an Emergency Mobile Alert), depending on how far away it is created, but the earthquake is still your best warning. An earthquake that could cause a regional source tsunami could be felt as rolling earthquake shaking of unusually long duration (longer than a minute). |
| Distant source tsunami |
Distant-source tsunamis are those that are generated greater than three hours travel time to the Christchurch and Banks Peninsula coast from around the Pacific Ocean. They could be as long as 16 hours travel time. Distant-source tsunamis could take as little as four hours to reach Christchurch and Banks Peninsula, such as those from the New Hebrides subduction zone near Vanuatu but are more likely to take at least 12 hours from other areas of the Pacific Ocean. Distant-source tsunamis from around the Pacific Ocean pose the most frequent tsunami threat to Christchurch and Banks Peninsula, however it is possible that distant-source tsunamis can be generated from other oceans. In terms of potential inundation, Christchurch city’s worst case tsunami threat is from a rare, very large magnitude ~9.45 earthquake off the coast of Peru. A large tsunami from Peru could reach Christchurch and Banks Peninsula in approximately 15.5 hours. Things to remember An earthquake across the Pacific Ocean would not be felt in Christchurch or Banks Peninsula. There will be time for an official warning from Civil Defence Emergency Management. |
| Other sources |
While most tsunami that could affect Christchurch are expected to be caused by earthquakes; there are other possible sources to be aware of. These include landslides, volcanic activity, and meteorite impacts. Although these events are considered less likely than earthquake-triggered tsunami, they remain credible hazards for Christchurch and Banks Peninsula. |
For more information on tsunamis visit the Environment Canterbury website.(external link)