The latest tsunami risk mapping shows the Kaikōura coast will possibly have very little warning, possibly just a few minutes, if there’s a large offshore quake.
New GNS mapping, commissioned by Environment Canterbury, has revealed a worst case scenario based on a one in 2500-year earthquake event.
On Tuesday night, Environment Canterbury’s natural hazard’s scientist, Helen Jack, met with the Kaikōura community to explain the new information to them, and show them the movement of a computer generated wave, triggered by a large earthquake at the southern end of the Hikurangi subduction zone.
Jack, who has studied earthquakes for the past 20 years, told the group: “It can be a little bit scary and it’s OK to be like ‘oh that’s quite a lot’.”
With that warning, she explained how a large tsunami could occur and played a motion graphic. “You can see the waves hitting the Kaikōura coast, you may only have 5 to 10 minutes before a tsunami arrives.”
She said: “We could, under a really worst case scenario, be looking at maybe up to 10, 20 metres, maybe even a little bit more, tsunami heights at the coast and on very steep coasts that can run up to maybe 50 metres above sea level.”
With the 2016 Kaikōura quake, that cut off the coastal town, still fresh in the mind of the community.
Glen Burridge, who lived up the coast at Kekerengu was taking notes to share the message with his community.
“The community’s interested in any measures in place and what we should be looking for. It makes sense to be prepared,” he said.
Kaikōura resident Erica O’Connor said she wanted to be at the meeting “for some peace of mind”.
“Because we live down the east end of Kaikōura and you just don’t know how a tsunami coming down is going to affect us.”
The new data has also expanded the area that could be affected by a tsunami wave.
Kaikōura District Council CEO Will Doughty said it was about “trying to raise awareness”.
“Particularly there’s a couple of communities Kekerengu in the north and Oaro in the south previously outside the zone but now inside in that worst case event.”
The council has placed signs along the waterfront to remind locals and tourists if there’s an earthquake they should head to higher ground. They’re also recommending people have a go bag ready at all time, along with an evacuation plan.
Kaikōura District Mayor Craig Mackle said: “It doesn’t hurt even for those who are oh it won’t happen in our time to be aware to know because you just don’t know”.
Meanwhile, Jack added officials “don’t want people to dwell on it”.
“What we want people to do is just have a think in advance about what you might need to take and where you would go.”
She also encouraged people to check the Get Ready website for information on evacuation zones.