Megathrust quake: Where exactly you should evacuate to in event of tsunami

Civil Defence is advising New Zealanders to be aware of tsunami evacuation zones following public reaction to a shocking tsunami simulation.

The computer simulation was based on the Hikurangi subduction zone and shows the entire east coast of the North Island hit by a huge tsunami.

Scientist William Power from GeoNet Science (GNS) said New Zealand should be concerned about the Hikurangi subduction zone due to its history.

"The largest earthquakes on the Hikurangi subduction zone in New Zealand's written history have only been around Magnitude 7.1 - two such earthquakes occurred in 1947, north of Gisborne," he told Newshub.

"Both of these caused tsunamis that affected about 100km of the coast of the East Cape. In the most strongly affected places, the run-up heights [the height reached onshore by the inundating water] reached about 10m."

Dr Power said while it's hard to predict when an earthquake will strike, New Zealanders should be prepared for the chance it could.

A still from the computer simulation.
A still from the computer simulation. Photo credit: Steven Ward / YouTube

Civil Defence says in the event of an earthquake, Kiwis should follow the "long or strong, get gone" message.

It advises that if an earthquake occurs near the coast, residents should drop, cover and hold until the shaking stops and then move to the nearest high ground as soon as possible.

In the case of an emergency, it's recommended to take a bike or walk, as the roads need to be saved for those who need them.

New Zealanders should be particularly aware of tsunami evacuation zones, which are predicted to be the areas where a tsunami could hit.

Pt Chevalier tsunami evacuation map.
Pt Chevalier tsunami evacuation map. Photo credit: Civil Defence

"[The zones] are based on scientific modelling of different tsunami sources and the areas that could be impacted by tsunami," Civil Defence spokesman Anthony Frith said. 

"Some regions have large sources very close to the coast, other regions face greater danger from tsunami that travel from across the Pacific.

"The evacuation zones take into account the direction and size of possible tsunami and scenarios. This means if you get out of the zones you are safe form tsunami waves, no matter what the scenario."

Civil Defence advice and tsunami evacuation zone maps by region: