Study a reminder of tsunami risk

Bluff man Noel Peterson worries about the potential of tsunami in his coastal town. PHOTO: LUISA...
Bluff man Noel Peterson worries about the potential of tsunami in his coastal town. PHOTO: LUISA GIRAO
A tsunami could bring wide-spread devastation to Southland, but that fact has led to a mixed bag of reactions — from real concern to a shrug of the shoulders.

A study published in New Zealand Journal of Geology and Geophysics, "A review of tsunami hazard for southern Aotearoa New Zealand with implications for the future" by University of Otago research associate professor Caroline Orchiston, Ursula Cochran and Ashleigh Vaus, showed Southland had some of the highest tsunami hazards in the country.

The study said that with a return period of 2500 years, much of the southern coast of Southland could expect tsunami heights of 8m-12m, and at a 500-year return period, the heights could be about 4m-8m.

"For Southland, tsunami hazards come predominantly from large earthquakes at the Puysegur Subduction Zone and from earthquakes offshore of Peru.

"While there will be about 14 hours warning of a tsunami triggered offshore of South America, the travel time for tsunamis from the Puysegur Subduction Zone is much shorter. Invercargill may have one to two hours’ notice."

Dr Orchiston said damaging tsunamis did not happen often, but when they did, it was important to know what to do to save lives.

"It’s more about preparedness and awareness for the community ... Just knowing that if they feel a strong earthquake they should move away from the coast.

"It’s still a low probability thing for a very large tsunami — this is very low risk — but there could be other smaller tsunami that people need to be aware about as well."

Speaking to the Otago Daily Times yesterday, residents of the coastal town of Bluff had mixed reactions.

Noel Peterson said he had always been very interested in the subject.

While he believed there was a low risk for a major tsunami strike, it was important to know where to go or what to do.

"‘When I moved from Tauranga to Bluff, I bought a house that’s 100m above sea level for a good reason.

"Even though it’s a low probability, I think educating the community is essential and having the signs more in their face in central and visible spaces is a must do."

He believed councils should lead the way in the conversation, and schools also had an important role to educate youth.

While Ema Hoeft said tsunami worries were not something she lost sleep over, she liked to be prepared and aware of the risks.

She said she started to pay more attention to the subject when she moved to Bluff from Auckland 7 years ago.

"It is something that we need to be aware of and I’ve become more aware once we moved here, as I realised we were living right by the water.

On the other hand, fisherman Duncan McCulloch said the risk of tsunamis did not faze him.

"I don’t worry about anything. I just live day-by-day. I don’t even watch the news.

"But if something happens, there are not many places we can go — it would just be up the hill, and I live most of the way up the hill."

Emergency Management Southland group controller Lucy Hicks said the recent study would further inform Southland’s response planning and ongoing plan reviews.

She stressed Invercargill did not have tsunami warning sirens, so people needed to know what to do.

"The life-saving message is, ‘if it’s long or strong, get gone’."

luisa.girao@odt.co.nz