List of tsunamis affecting New Zealand facts for kids

Tsunamis are giant ocean waves usually caused by powerful movements under the sea. These movements can be from big earthquakes, underwater landslides, volcanoes erupting, or even meteor impacts. New Zealand's coastline is often affected by tsunamis because the country sits on the edge of the Pacific Plate, a very active part of the Earth's crust. This area is also known as the Pacific Ring of Fire.

Tsunamis can come from earthquakes happening close to New Zealand or from far away places like South America, Japan, and Alaska. On average, New Zealand experiences at least one tsunami with waves higher than one metre every ten years. We know about past tsunamis from written records that started in the 1800s, but also from Māori oral stories and scientific studies of ancient tsunami deposits. Scientists are also looking into possible tsunamis in large inland lakes, especially those caused by landslides.

The Pacific Plate

Tsunami travel times

Major Tsunamis in New Zealand's History

New Zealand is very close to the Pacific Ring of Fire, which means it often experiences tsunamis from many earthquakes. The biggest tsunamis that affect New Zealand usually come from huge earthquakes in the Hikurangi Margin, a major area where one Earth plate slides under another.

Tsunamis Caused by Earthquakes

Major active fault zones of New Zealand.

Ancient Tsunami: Southern Hikurangi Margin (880–800 years ago)

Scientists have found evidence of a tsunami that was at least 3.3 metres high. It hit Big Lagoon, near Blenheim, about 800 to 880 years ago. This giant wave was likely caused by a huge earthquake on the southern Hikurangi Margin.

The 1820 Southland Tsunami

According to Māori stories, hundreds of Kāti Māmoe Māori people died in a tsunami in the 1820s. They were walking along the beach near Orepuki after gathering fish. The beach is between the sea and cliffs, so even a moderate tsunami of 2 to 4 metres high could have caused many deaths. This tsunami might have come from an earthquake on the Fiordland or Puysegur faults.

The 1826 Fiordland Earthquake and Tsunami

In 1826, seal hunters in Dusky Sound felt a very strong earthquake. It caused many landslides and lifted parts of the land. A tsunami or large wave, caused by this uplift, hit the area where the sealers were. Its exact size isn't known, but it was big enough (over 1 metre) to make the sealers worry that their small island would be covered by water.

The 1855 West Wairarapa Tsunami

On January 23, 1855, a huge earthquake tilted the Wellington Region, including Wellington Harbour. The eastern side of the harbour rose about 80 centimetres higher than the western side. This pushed water onto the shore along Lambton Quay, flooding homes and shops.

In Cook Strait, the land moved even more. The Remutaka Range rose about 6 metres, lifting the seafloor of the strait. The tsunami's exact maximum height isn't known, but sheds at Te Kopi, South Wairarapa, which were 8 metres above sea level, were destroyed. The tsunami affected areas as far north as Otaki and parts of the upper South Island.

About 20 minutes after the earthquake, a 3-4-metre high tsunami entered Wellington harbour. It also flowed across the Lyall Bay to Kilbirnie area, where the water was about 1 metre deep. Captain Byron Drury of the ship HMS Pandora reported: "For eight hours... the tide approached and receded from the shore every 20 minutes, rising from eight to ten feet and receding four feet lower than at spring tides." The earthquake and tsunami destroyed the bridge over the Hutt River. Ships entering Wellington harbour after the tsunami reported sailing through many dead fish.

The 1868 Chile Tsunami

On August 13, 1868, a large earthquake happened near Arica, which was then part of Peru (now Chile). The tsunami it created reached New Zealand 15 hours later, causing a lot of damage on the Chatham Islands and Banks Peninsula. It also affected many places along New Zealand's eastern coast, from Great Barrier Island to Bluff. The tide at Wellington and Port Chalmers rose and fell by over a metre for about 2 hours.

The Chatham Islands were hit first, around 1 am on August 15. The Māori village of Tupuangi was completely destroyed, with only sand and seaweed left. Luckily, the first wave was small enough to wake the villagers, allowing them to get to safety before bigger waves arrived. A Māori man drowned trying to save a boat. Buildings at Waitangi were also damaged.

Around 4 am, a night watchman at Lyttelton noticed a ship, the John Knox, was nearly touching the jetty because the water had gone out. He woke the captain, who saw that Lyttelton Harbour was almost dry. Minutes later, a huge wave crashed into the harbour. This powerful wave snapped boat ropes, broke the John Knox's mooring chain, and pushed it into the jetty. It also damaged other ships. The tide kept rising and falling in the harbour for hours. The tsunami that entered the harbour was estimated to be 7 metres high, though the captain thought it was 2.5 metres high.

The bays around Banks Peninsula were also hit. The tsunami travelled far inland along valleys, damaging homes and carrying away bridges and fences. At Pigeon Bay, a series of waves up to two metres above the highest tide carried away jetties, timber, a boat house, and fences.

After this tsunami, Ferdinand von Hochstetter studied it in detail. He tracked its journey across the Pacific Ocean, figuring out how fast the waves travelled and the ocean depth. This was the first detailed scientific study of a major tsunami.

The 1877 Iquique Tsunami

On May 10, 1877, a powerful earthquake happened near Iquique, Peru (now Chile). The tsunami it caused reached New Zealand's eastern coast between 7 and 8 am on May 11. The waves were reported to be 1–2 metres high in most places, affecting the coast from the Bay of Islands to Bluff. It also reached Westport on the West Coast. At Akaroa and Gisborne, the waves were 2–3 metres high, and at Port Charles on the Coromandel Peninsula, they were over 3 metres high.

Because of what they learned from the 1868 tsunami, newspapers quickly guessed that the wave came from a South American earthquake. This was confirmed a few days later when news of the Iquique earthquake arrived.

The 1929 Whitecliffs, Karamea Tsunami

On June 17, 1929, a 2.5-metre-high tsunami was created by the powerful Murchison earthquake.

The 1931 Napier Tsunami

The 1931 Napier earthquake caused a landslide at Waikare, which then created a local tsunami that was an amazing 15.3 metres high! At Napier itself, the tsunami was about 3 metres high.

The 1947 Gisborne Tsunamis

March 26, 1947

On March 26, 1947, at 8:32 am, Gisborne felt a small earthquake. Within 30 minutes, the coast from Muriwai to Tolaga Bay was hit by a tsunami that reached 10 metres high at Turihaua. At Tatapouri Point, four people at a hotel escaped by running to higher ground. Two waves crashed through the hotel's ground floor, and several small buildings were washed away. Two men in a cottage at Turihaua were swept inland onto the coast road, but they were safe. The cottage was completely destroyed except for the kitchen they were in. No one was killed. The earthquake that caused this tsunami was a magnitude 7-7.1 quake offshore near Poverty Bay.

May 17, 1947

On May 17, 1947, another tsunami hit the coast between Gisborne and Tolaga Bay. This one reached a maximum height of 6 metres north of Gisborne. Again, no one was hurt. This tsunami had less impact because it happened at low tide. The earthquake responsible was a magnitude 6.9-7.1 quake offshore near Tolaga Bay.

The 1960 Chile Tsunami

A tsunami caused by a massive magnitude 9.5 earthquake in Valdivia, Chile, on May 23, 1960, was reported at over 120 places in New Zealand. Like the earlier Chilean tsunamis, it affected New Zealand's eastern coast from Cape Reinga to Stewart Island. What was unusual was that its effects were also seen on the west coast of both islands, including Ahipara, Whanganui, and Nelson. At the Chatham Islands and Campbell Island, water heights above sea level ranged from 3 metres to over 5 metres.

The Pacific Tsunami Warning Center warned New Zealand authorities about the approaching tsunami. This led to the first major tsunami evacuation in New Zealand's history. Port facilities along the east coast were cleared, schools in coastal areas closed, and towns like Whitianga, Whakatāne, and Kaikōura were evacuated.

The 2009 Fiordland Tsunami

Tsunami warnings were issued after this earthquake by authorities in New Zealand, Australia, and Hawaii. Civil defence officials in Southland also warned of a "potential tsunami." The tsunami reached a height of 1 metre in Jackson Bay. Warnings were later cancelled or reduced.

The 2010 Chile Tsunami

New Zealand's Civil Defence reported waves of 50 centimetres in the Chatham Islands, with later surges of 2 metres there. A surge 2.2 metres high hit the South Island's Banks Peninsula, while surges up to 1 metre high were reported in the northern North Island.

The 2016 Kaikōura Tsunami

A tsunami caused by the Kaikōura earthquake was recorded at 2.5 metres high at Kaikōura. An investigation showed it was 1 metre high at the nearest recording point. At Little Pigeon Bay on Banks Peninsula, the tsunami reached 4.1 metres above sea level, badly damaging an empty beachside cottage. It also travelled 140 metres up a nearby creek.

Tsunamis Caused by Landslides

Sonar mapping has found huge underwater landslides near the New Zealand coast. These landslides would have caused large local tsunamis. Researchers believe some landslides in the Tasman Sea millions of years ago could have caused tsunamis up to 70 metres high along the west coast of the North Island.

The 1987 Doubtful Sound Tsunami

A 3-metre-high local tsunami was caused by a landslide into Deep Cove, Doubtful Sound, in May 1987.

The 2003 Charles Sound Tsunami

During the magnitude 7 2003 Fiordland earthquake on August 23, a significant landslide crashed into Charles Sound. This caused a 4 to 5 metre high tsunami that damaged a wharf and helipad in the Sound. This tsunami was only local, affecting a few hundred metres of coastline.

Tsunamis Caused by Volcanoes

The 180 Taupo Eruption Tsunami

Even though the Taupo eruption was inland, it was so powerful that it created a huge air pressure wave. This wave was strong enough to cause a tsunami. Scientists have found evidence of ancient tsunamis in the Cook Strait area that might be linked to this eruption.

The 1883 Krakatoa Tsunami

The massive eruption of the Krakatoa volcano in Indonesia created a type of wave called a "rissaga" (a weather-related tsunami) that was up to 2 metres high on the New Zealand coast.

The 2022 Hunga Tonga Tsunami

The eruption of the Hunga Tonga–Hunga Ha'apai volcano in January 2022 caused a tsunami that hit New Zealand. Combined with a storm surge from Cyclone Cody, it caused a lot of damage at a marina in Tutukaka. Waves pulled boats from their moorings, sinking some and smashing others together. The total damage was estimated to be worth millions of dollars.

The tsunami struck Great Barrier Island around 1:05 am to 1:10 am local time, with a height of 1.33 metres. It caused flooding at Mahinepua Bay, where a campsite was located, but all 50 people there were safe. People fishing in Hokianga Harbour had to run to escape the waves and reported driving through water over 1 metre deep. Unusual waves were also recorded in Port Taranaki in New Plymouth. No one was hurt in New Zealand.

Tsunamis from Meteors

The Chicxulub Impact Tsunami

The Chicxulub asteroid impact near the Yucatán Peninsula 66 million years ago is thought to have created a global tsunami that was 30,000 times bigger than recent tsunamis. Scientists believe they have found evidence of this ancient tsunami in rock layers on the southeast corner of the North Island and northeast corner of the South Island.

The Eltanin Impact Tsunami

The Eltanin impact was a meteor that hit the eastern part of the South Pacific Ocean about 2.5 million years ago. It is believed to have caused a very large tsunami along New Zealand's coastline.

The Mahuika Impact Tsunami

There is some debate about whether a huge tsunami, possibly over 30 metres high, hit Stewart Island in the 15th century. Some believe this was caused by a meteor impact.

Tsunamis with Unknown Causes

East Coast, North Island (200, 800, and 1600s)

A study in 2016 found evidence of three or four large tsunamis with waves between 9 and 12 metres that hit Puatai Beach on the East Coast of the North Island. While they were likely caused by earthquakes, their exact cause and timing are still being investigated.

Western Waikato (1320–1450)

A tsunami event sometime between 1320 and 1450 is thought to have affected 150 kilometres of the Western Waikato coastline. It might have been caused by an underwater landslide from the Aotea Seamount, about 240 kilometres west of Raglan. Evidence comes from marine gravel found at 32 sites along the coast.

A Māori legend from the New Plymouth area, called "Coming of the Sand," describes a possible tsunami that flooded inland areas and left a thick layer of sand.

South Taranaki Bight (1470–1510)

A tsunami that happened between 1470 and 1510 in the South Taranaki Bight might have reached as far south as Abel Tasman National Park. Evidence of this tsunami has been found on D'Urville and Kapiti Islands, and at Waitori in South Taranaki.

Māori Settlements Moved (1500s)

During the 1500s, Māori people moved their settlements from low-lying coastal areas to inland or hilltop sites. Scientists believe this change was due to tsunamis. Archaeological digs at old coastal settlements show tsunami damage in many places.

D'Urville Island (Early 1800s)

In the early 1800s, the Māori village of Moawhitu on D'Urville Island was wiped out by what Māori oral traditions describe as a large wave, now thought to be a tsunami. The exact date of this event is unknown.

Chatham Islands (1924)

On July 19, 1924, the northern and eastern sides of Chatham Island and Pitt Island were hit by a series of waves that reached 6 metres above the high-water mark. At Kaingaroa, the waves went 100 metres inland, destroying a dam and two fishing boats. A bridge was badly damaged at Wharekauri, and fences were washed away. On Pitt Island, the wharf was destroyed. The cause of this tsunami is unknown; it could have been a landslide or an unrecorded earthquake.

How New Zealand Prepares for Tsunamis

There is evidence that Māori people moved their coastal villages to safer, higher ground in the 1500s because of tsunamis. Early European settlers didn't fully understand the danger until the 1868 and 1877 tsunamis.

Modern warning systems began after the 1946 Aleutian earthquake. The National Oceanic and Atmospheric Administration Pacific Tsunami Warning Centre was set up in 1949, and New Zealand became a member. This means New Zealand gets warnings about tsunamis caused by distant earthquakes.

The Pacific Tsunami Warning and Mitigation System was created in 1965 because of the 1960 Chile tsunami. New Zealand is one of its 46 member countries.

Tsunamis caused by earthquakes close to New Zealand can arrive within minutes. This is often not enough time for GeoNet to find the earthquake, figure out if it will cause a tsunami, and tell the Ministry of Civil Defence and Emergency Management to issue warnings.

In 2016, it took Civil Defence over an hour to warn about a possible tsunami from an earthquake near Te Araroa. This led to calls for the warning system to be improved.

Different parts of New Zealand have different ways of warning people. For example, Christchurch installed a large system of tsunami warning sirens in 2012, but the Wellington region does not have any.

After the 2004 Indian Ocean tsunami, New Zealand started installing sea-based tsunami warning devices. Now, gauges are in place at most of the 20 selected sites.

The Pacific Tsunami Warning Centre's ocean-based devices mainly focus on protecting Alaska, Hawaii, and the United States Pacific coastline. This leaves a gap in the Southern Ocean. Australia installed a DART buoy in the south-east Tasman Sea to help cover that area. There are now twelve DART buoys in the southwestern Pacific Ocean, focusing on major underwater trenches like Hikurangi and Kermadec. However, there are no New Zealand DART buoys in the Tasman Sea or south of New Zealand.

The Blue Line Project

Wellington was the first place in New Zealand to paint blue lines on its roads. These lines show how far inland a potential tsunami might reach. This project won awards and sparked international interest.

See also

• List of earthquakes in New Zealand