What to Expect During a Tsunami in New Zealand | Sequence of Events and How to Survive It

If you are near the coast in New Zealand and feel an earthquake that is strong enough to make standing difficult, or weak rolling shaking that lasts a minute or longer, protect yourself during the shaking and then evacuate immediately. Once the shaking stops, move to the nearest high ground or as far inland as possible, outside the tsunami evacuation zones. Do not wait for an official warning, a siren or a visible wave. New Zealand Civil Defence summarises this life-saving action as “Long or Strong, Get Gone.”

Other natural signs also demand immediate action: a sudden and unusual rise or fall in the sea, or loud unusual sounds from the water. These signs are not guaranteed to occur. If you receive an official tsunami evacuation instruction without feeling an earthquake, act on it immediately. Read Get Ready’s official tsunami guidance and check your location on the national tsunami evacuation-zone map. For someone in immediate danger or seriously injured, 111 reaches New Zealand’s Police, Fire and Ambulance emergency services.

Quick answer: A tsunami may be generated by a nearby earthquake, a distant earthquake or another disturbance of water. People close to the source may have only minutes to leave; there may not be time for a formal warning. A distant-source tsunami may allow more time for National Emergency Management Agency (NEMA) warnings. The hazard often consists of repeated surges and strong currents, not one movie-like breaking wave. Water can remain dangerous long after the first arrival, and only an official all-clear permits return.

Ten actions to read first: the tsunami survival checklist

1. Earthquake shaking? Drop, Cover and Hold first. Protect your head and body until shaking stops.
2. Long or Strong? Get Gone. Near the coast, evacuate immediately to high ground or far inland after strong or prolonged shaking.
3. Do not wait to see the ocean withdraw. Not every tsunami has a visible drawdown or a dramatic crest.
4. Walk, run or cycle if you can, using local evacuation routes and avoiding earthquake-damaged roads; reduce traffic congestion.
5. Help children and people with mobility needs move early without delaying the whole evacuation to collect nonessential possessions.
6. Avoid beaches, estuaries, river mouths, tidal channels, marinas and low-lying coastal roads.
7. Keep away from the sea after reaching safety. The first surge may not be the largest and currents can continue between arrivals.
8. Follow NEMA and your local Civil Defence Emergency Management (CDEM) Group’s current messages.
9. Do not return until Civil Defence gives an official all-clear. Get Ready additionally advises staying clear of coastal water and tidal waterways for at least 24 hours after a tsunami or tsunami warning.
10. For life-threatening injuries or immediate rescue, call 111 with your exact location; do not attempt an untrained rescue in moving water.

Stage 1 — Before the event: understand the coast and your evacuation zone

New Zealand has extensive coastline facing multiple offshore earthquake and tsunami sources. A person’s exposure depends on shoreline shape, elevation, nearby rivers, local geology and the tsunami’s origin. A beach, estuary, harbour, marina and low coastal town may face different dangers during the same event.

The correct preparation question is not simply “How far from the sea am I?” It is “Does my home, school, workplace, campsite or usual route lie within a mapped tsunami evacuation zone, and where is the nearest safe exit?” Distance inland alone is not a reliable substitute for a local evacuation map.

The official Get Ready tsunami-zone map lets residents search by address. It describes evacuation zones that may be activated for different sizes or types of tsunami. It is important to understand a detail that users can easily miss: the map shows evacuation zones, not current tsunami warnings.

Some localities also display tsunami evacuation-route signs. Learn the routes before an earthquake makes roads difficult to recognise. Practise a family evacuation walk, known in Aotearoa New Zealand as a tsunami hīkoi. A route that takes only a few minutes in ordinary conditions may become more difficult among fallen glass, damaged footpaths and frightened crowds.

Stage 2 — An earthquake begins: the natural warning may be all you get

If an earthquake occurs, Drop, Cover and Hold in a position appropriate to your body and surroundings. Protect your head and neck against falling items. Do not rush down stairs or out past unstable façades during violent shaking. If you cannot safely drop to the floor because of disability or mobility constraints, use the supported protective position you have practised.

The National Emergency Management Agency’s response guidance identifies two important natural earthquake triggers: strong shaking that makes it hard to stand, or weak, rolling shaking that lasts a minute or longer. Either signal near the coast justifies immediate tsunami evacuation once shaking stops.

The coast does not need to look unusual yet. A nearby source may send dangerous water toward shore within minutes. You do not have to identify the fault, magnitude or earthquake depth before acting. If you wait to check a map of the epicentre, a local tsunami could already be on its way.

A phone may not sound an alert. Networks and sirens may not have time to respond. This is precisely why New Zealand teaches people to act on the natural warning themselves.

Stage 3 — The first safe seconds after shaking: decide to move

Once shaking has stopped enough for safe movement, begin your evacuation out of the tsunami-risk zone. If a recognised route is available, follow it. Move to the nearest high ground or as far inland as possible. When you cannot fully leave the zone, go as far or as high as you can; every metre of safer movement can matter.

Do not delay to put furniture upright, collect passports from a distant room or search for pets that are not already with you. Take a small grab bag only if it is immediately accessible. A person who left the beach for higher ground should not return to the shoreline to collect a parked vehicle.

Walk, run or cycle when practical and physically possible. This reduces the risk of traffic congestion on roads potentially damaged by the earthquake. Emergency vehicles and transport for people with mobility impairments may require road access.

If you must drive because of disability or another significant constraint, use the locally recommended route and keep moving beyond the evacuation zones if instructed, allowing others to leave. Do not park at the first high ground if that blocks the only route for vehicles behind you.

Stage 4 — The sea may give other signs, but they are not a countdown

An earthquake is not the only warning sign. You may notice the sea rise or fall abruptly, hear an unusual roar or see water behave in a way inconsistent with ordinary waves. A person near the water who experiences these signs should evacuate immediately, even without having felt an earthquake.

However, the absence of these signs proves nothing. Some tsunamis arrive without a dramatic withdrawal of the water. The first visible effect may be rapidly increasing current, sudden flooding or unusual surges entering a harbour.

A tsunami is often misunderstood as a single huge curling wave. In reality, the energy can appear as a powerful rise and fall of water level or a series of turbulent flows. It may be particularly dangerous in harbours and narrow channels, where currents can move vessels and floating debris.

Do not stand on a wharf, harbour wall, bridge or estuary bank to watch for the first movement. Curiosity can place a person directly where the tsunami becomes most hazardous.

Stage 5 — Local, regional and distant sources: why warning time differs

A local-source tsunami begins close to New Zealand. It can arrive so quickly that there is not time for an official alert before people must move. Recognising natural signs is therefore crucial.

A regional-source tsunami may travel from a source some distance away, potentially allowing authorities time to evaluate measurements and warn people. A distant-source tsunami generated farther across the ocean may provide a longer interval for formal warnings and planned movement.

NEMA is the official tsunami warning agency for New Zealand. As explained in its tsunami detection and warning-system information, monitoring and analysis support official decisions about possible coastal impact.

Do not use the type of source as permission to delay. If you feel long or strong shaking near the coast, act immediately without calculating the source. If a formal warning from a distant earthquake instructs your location to evacuate, leave even though you felt no shaking.

Stage 6 — Understanding official messages and evacuation-zone colours

New Zealand’s Civil Defence system includes national and regional channels. NEMA publishes national tsunami warnings; local CDEM Groups provide community advice, route information and instructions. Alerts may be carried by television, radio, official websites, loudhailers and sometimes an Emergency Mobile Alert.

A tsunami evacuation-zone map may show different colours such as red, orange and yellow, indicating different areas at risk under different tsunami scenarios. The official nationwide zone map explains the precise interpretation of these categories.

But colour on an evacuation-zone map is not the same thing as the colour or wording of a current warning. The map is for location preparedness. A current message tells people which zones or places must move now.

During a local natural-warning event, do not delay to check whether your precise home is in the outermost mapped category. Get out of the danger area promptly and use the official map or local signage only if it does not slow a life-saving evacuation.

When the formal warning arrives after people have left, use it to decide whether to remain at the safe location and how to obtain further updates. Do not reverse the evacuation because another person’s phone did not alert.

Stage 7 — What happens when the water reaches a harbour or coastline?

Strong currents may suddenly push water into marinas, harbours, estuaries and coastal rivers. Boats may break their moorings, debris can move rapidly, and waterfront structures may be damaged. The behaviour may look different in a small bay compared with an open beach.

A person who has already reached high ground should stay there. Do not move toward the water to check whether the evacuation was necessary. Seeing a small first surge does not mean the later ones will be harmless.

Tsunamis can move upstream along tidal rivers and creeks, creating dangers beyond the beach. A bridge crossing a tidal channel may be in a hazard zone even when it is some distance from the open coast.

A vehicle moving on a low coastal road may face water, floating debris and loss of road support. Do not drive across a flooded section or assume that a larger vehicle can safely handle the current.

Stage 8 — Repeated waves and currents: the first arrival is not the end

A tsunami commonly involves multiple waves or surges. They may be separated in time, and the first is not necessarily the largest. Dangerous currents can continue between peaks. A period when the beach looks calm may be part of the hazardous sequence rather than a safe pause.

Do not return to the harbour, estuary, river mouth or beach after the first wave recedes. An exposed seabed or newly dry street may flood again. Keep children, pets and others away from the water while the warning remains active.

Official New Zealand advice says to stay away from coastal waters, tidal estuaries, rivers and streams for at least 24 hours after any tsunami or tsunami warning, because even relatively small waves can create dangerous currents. That is a minimum precaution, not an automatic all-clear after 24 hours. Follow Civil Defence instructions about actual re-entry.

The exact duration of dangerous currents depends on the source and local geography. No generic article can promise that the beach will be safe at a particular clock time.

Stage 9 — If earthquake damage blocks the evacuation route

A local tsunami may follow an earthquake that also damages buildings, roads, bridges and power infrastructure. A normally safe evacuation route might now have fallen masonry, broken power lines or a weakened bridge. The best alternative depends on the actual terrain.

If a road is blocked, use another recognised route if safely available, moving away from the coastline and low drainage channels. Do not walk through unstable buildings or cross live wires to shorten the journey.

People with mobility limitations may need assisted transport or support on damaged footpaths. This should be planned beforehand, but if the event has begun, alert responders and use the safest feasible movement. New Zealand’s guidance emphasises the best form of Drop, Cover and Hold is the one the individual can actually perform, and evacuation needs similar practical planning.

If you cannot reach the mapped safe zone, move as far or high as you safely can and make your situation known. This is a last-resort response, not proof that every ordinary tall building is an approved tsunami evacuation structure.

Stage 10 — Schools, childcare and family reunification

Schools and childcare centres near the coast need a tsunami plan that identifies the safe location, staff responsibilities and arrangements for students who require assistance. A parent should know the site’s plan before an event, including how children will be released afterward.

During a local earthquake and tsunami warning, do not drive back into an evacuation zone to collect a child from a school that is already implementing an official evacuation. Such a journey can add traffic congestion and put both parent and child at risk.

Teachers should give concise instructions: protect yourself during the shaking; when safe to move, follow the group’s evacuation route; stay together at the safe assembly point. A person who becomes separated should seek help from authorised adults rather than trying to return to the school building.

Families can arrange an out-of-area contact and send one brief text saying where they are safe if mobile service works. Do not post children’s personal location or medical details publicly while trying to coordinate help.

Stage 11 — Tourism, beaches, camping, boats and coastal work

New Zealand visitors may spend time at beaches, coastal walks, holiday parks, harbour restaurants or isolated campsites. Some are unfamiliar with the words “tsunami evacuation zone” or the local Civil Defence signs.

Before an overnight stay near the coast, identify the nearest route out of the evacuation zone. Learn the location of any local safe elevated area rather than assuming that the nearest steep-looking hillside is stable after an earthquake.

People working in fishing ports, marinas and coastal facilities must understand that boats and property are secondary to evacuation. Do not return to secure ropes or move a vessel while the coastal hazard is active. People at sea have different safety considerations from people in harbours; follow maritime radio, harbourmaster and official marine instructions rather than trying to apply a land evacuation route to a vessel.

If you are driving near a beach when a warning occurs, avoid making an unnecessary vehicle queue at the only exit. Walk or cycle when feasible and in accordance with local instructions. A visitor should not use a drone or video recording as a reason to linger by the water.

Stage 12 — Lakes can experience tsunami-like waves too

New Zealand Civil Defence explains that lake tsunamis can occur in some large bodies of water, potentially triggered by earthquakes, landslides, rockfalls, volcanic processes or other sudden displacements. A mountain lake is therefore not automatically safe from sudden destructive waves.

If you are at a lakeshore and feel long or strong shaking, hear unusual water or rockfall sounds, or see a sudden unusual rise or fall of water, move away from the shore toward higher safe ground immediately.

Be particularly alert to landslide-prone slopes around lakes after an earthquake. A landslide entering the water can create a wave without a large earthquake. Avoid approaching damaged slopes or a newly formed deposit to photograph it.

The local lake geography determines exposure and safe movement. A coastal tsunami evacuation map may not apply directly to an inland lake, so follow local emergency management information.

Stage 13 — The first hours after evacuation: stay safe at the high-ground location

Once outside the tsunami-risk zone, remain at a suitable safe place, keep everyone accounted for and listen for official instructions. A safe hilltop may have limited drinking water, shelter, toilets or phone reception, especially if many people arrive in a short time.

Carry a small grab bag only if doing so did not delay escape. Useful items include regular medicines, a warm or waterproof layer, sturdy footwear, safe water, phone power, infant needs and essential accessibility supplies. Do not return into an evacuation zone to recover a bag that was forgotten.

Keep children with known caregivers and ask local officials about designated shelters or welfare centres. People may feel frightened after strong shaking; clear information about when and where they can obtain help is more useful than unverified predictions of the next wave.

If someone is injured, call 111 when urgent professional help is needed. Give the safe location’s address, landmark or coordinates. Do not approach a hazard area to obtain a more precise position for dispatch.

Stage 14 — More shaking: another earthquake could renew the danger

If a tsunami follows a significant earthquake, aftershocks may occur. Some aftershocks can be powerful, cause additional structural damage or generate additional tsunami hazards. The risk does not necessarily end when the first earthquake’s shaking stops.

If shaking occurs while at the safe location, protect yourself again and avoid unstable slopes, trees or structures. Keep away from the evacuated coast and continue following Civil Defence messages.

If an alert is cancelled, read its exact location and meaning. Different coastlines or harbours can have different remaining risks. A cancellation for marine currents in one region may not constitute permission to enter every evacuated area.

Check the timestamp of official information and avoid forwarding an out-of-date map or warning screenshot as if it were current.

Stage 15 — Return and recovery: water recedes before the danger is finished

Only return when your CDEM Group or other authorised agency issues an official all-clear. Even then, roads, electrical systems, drinking water and buildings may require inspection. Floodwater can leave contaminated mud and debris or damage foundations.

Do not enter a building that appears structurally compromised or contains exposed wiring. Avoid flooded roads, bridges and unstable sea walls. Follow utility and public-health notices about water safety. Boiling can reduce many biological contaminants, but it does not remove fuel or every dissolved chemical.

When access is approved, photograph property damage safely and contact insurers or landlords as appropriate. Do not climb over barriers or enter a closed waterfront area solely to retrieve a vehicle or boat.

Communities may need weeks or months to restore roads, harbours, coastal businesses, homes and emergency services after severe impacts. Recovery also includes reviewing whether evacuation signage, safe routes and support for people with disabilities worked in practice.

Two illustrative situations: a family and a visiting couple

Example A — A family on a North Island coastal street: The ground shakes strongly enough that standing is difficult. The family protects itself until shaking stops and immediately begins the evacuation walk it has practised. They do not wait for a phone alert or collect a vehicle parked close to the beach. When they reach high ground, they stay there while authorities assess the risk.

Example B — Visitors near a South Island harbour: The couple does not feel an earthquake but receives an official tsunami warning. They use local route signs to leave the waterfront rather than watch the harbour. The first visible water movement looks small, but they remain at the safe site until Civil Defence issues its all-clear.

These examples are hypothetical and are not current evacuation notices for any town, harbour or region.

Eight misconceptions to correct

1. “No official alert means no tsunami can arrive.” Local tsunami can arrive before any formal warning.
2. “A tsunami always starts with the sea draining away.” It may arrive without that sign.
3. “I must calculate the earthquake magnitude before leaving.” Long or strong shaking near the coast is enough to act.
4. “Driving is always the quickest evacuation method.” Congestion and earthquake-damaged roads may make walking, running or cycling safer.
5. “The first wave is small, so the rest will be small.” Later surges and currents can be dangerous.
6. “The zone map is a live warning map.” It shows evacuation zones, not current alerts.
7. “Twenty-four hours means automatic safety.” Follow the official all-clear; the 24-hour precaution does not replace it.
8. “My pet or car must be collected before I leave.” Delays can endanger lives; leave possessions and do not return for animals that are not at hand.

New Zealand coastal preparation checklist

• Find your home, school, workplace and holiday accommodation on the official tsunami evacuation map.
• Practise your tsunami hīkoi to high ground or outside the evacuation zone.
• Teach everyone “Long or Strong, Get Gone.”
• Practise Drop, Cover and Hold in a way suited to each person’s mobility.
• Arrange accessible support for children, older relatives and people with disabilities.
• Keep medicine, warm clothing, water, shoes and a charged communication method accessible without delaying evacuation.
• Identify an out-of-area family contact and how schools will communicate.
• Follow NEMA/Civil Defence official warnings and local CDEM channels.
• Know 111 for urgent police, fire or ambulance help.
• Stay away from water for at least 24 hours after a tsunami or warning and until Civil Defence gives the applicable all-clear.

Frequently asked questions

What does “Long or Strong, Get Gone” mean?

After earthquake shaking that is strong enough to make standing difficult or lasts about a minute or longer, people near the coast should evacuate immediately once shaking stops, moving to high ground or as far inland as possible.

Should I wait for an Emergency Mobile Alert after a strong earthquake?

No. A nearby tsunami may arrive within minutes, too soon for an alert. Natural warning signs justify self-evacuation.

Can I use my car to evacuate?

Walk, run or cycle when practical to reduce traffic. Vehicles may be necessary for people with limited mobility; follow local evacuation arrangements and keep roads available for others.

Is the first tsunami wave always the largest?

No. Tsunami can involve repeated waves and currents, with significant hazards continuing after the first arrival.

How long should I stay away from the coast?

Until an official all-clear. New Zealand Civil Defence additionally advises avoiding coastal water, tidal estuaries, rivers and streams for at least 24 hours after a tsunami or tsunami warning; do not treat 24 hours as automatic permission to return.

Are lakes in New Zealand also at risk?

Some lakes can experience damaging waves generated by landslides, earthquakes or other sudden displacement of water. Follow natural warning signs and local emergency instructions near large lakes.

What emergency number should I dial?

111 for urgent Police, Fire or Ambulance services in New Zealand. The operator will ask which service is needed.

Official sources and connected reading

• Get Ready New Zealand — Tsunami: official natural warning signs and immediate actions.
• Get Ready — National Tsunami Evacuation Zones Map: address-based evacuation preparedness; not a live warning map.
• National Emergency Management Agency — Tsunami Response Messages: evacuation, walking and transport, water and rescue.
• NEMA — Tsunami Detection and Warning Network: how scientific detection supports official warnings.
• New Zealand Civil Defence: official emergency warnings and regional contacts.
• New Zealand Police — Emergency 111: official police, fire and ambulance emergency number.
• Get Ready — Trust Your Danger Sense: natural signs, immediate movement and the importance of not waiting for alerts.
• eduKateSG — Tsunami in Indonesia: compare another national warning system and tsunami evacuation decisions.
• eduKateSG — Earthquake in Japan: earthquake protection before coastal evacuation.
• eduKateSG — Glacial Lake Outburst Flood in Bhutan: a distinct fast-moving water hazard involving mountain lakes and river valleys.

Reader note — updated 6 November 2026: This is general tsunami-preparedness education and is not a real-time New Zealand tsunami warning or evacuation order. Natural warning signs, NEMA, your local CDEM Group and emergency responders take priority over this article.