New Zealand’s largest fault, the Hikurangi subduction zone. Image/East Coast LAB

PAM GRAHAM
pam.graham@age.co.nz

Wairarapa is involved in a project to co-ordinate planning across the eastern lower North Island for a rupture of New Zealand’s largest fault – the Hikurangi subduction zone.

Scientists say it’s a case of when, not if, the fault will rupture and a “credible magnitude 8.9 earthquake and tsunami scenario” is being used by the five Civil Defence emergency management groups involved.

The development of the Hikurangi Response Plan is being led by the East Coast Life at the Boundary.

The plan will outline how to respond to a Hikurangi subduction zone earthquake and tsunami, and how to enhance communities’ preparedness for such an event, said project lead Natasha Goldring, who is Hawke’s Bay-based.

“The scenario we are using to support the development of this response plan is a very realistic example of what we could face in our lifetime, or that of our children and grandchildren,” Goldring said.

The launch of the project comes in response to research in the past several years, which is ongoing.

The Times-Age has previously reported there are 100 international scientists involved in unprecedented local and international research into the subduction zone.

Scientists on board NIWA’s research ship R/V Tangaroa have been part of it.

Institutions involved are GNS Science, Victoria University of Wellington, Lamont Doherty Earth Observatory [US], Scripps Institution of Oceanography [US], as well as Tohoku, Kyoto and Tokyo Universities in Japan.

One focus has been slow-slips, which are movements of tectonic plates over weeks and months.

The world’s shallowest slow slip occurs just offshore near Gisborne.

A spokeswoman for Wellington Region Emergency Management Office said on Thursday that there is Wairarapa involvement in development of the Hikurangi Response Plan.

“We are working across regional boundaries,” she said.

This is appreciation that a Hikurangi event will be a wide one and “how do we come together in the lower and eastern North Island to respond to this”.

“We are just starting this project now. We are starting to raise awareness about it and are looking to engage with communities.”