The investigation of a significant fault adjacent to Wairarapa’s coastline is part of a major new research project looking at the potential repercussions of future earthquakes.
The project’s $12,670,372 of funding is being provided through the 2023 Endeavour Fund administered by the Ministry of Business, Innovation and Employment.
Te Herenga Waka – Victoria University of Wellington associate professor Jamie Howarth said a large earthquake could “set the scene for decades of further massive shakes”.
“Central Aotearoa sits in a zone of complex faulting known as the ‘transition zone’ because it marks the transition between our two largest plate boundary faults – the Hikurangi Subduction Zone and the Alpine Fault,” Howarth said.
The Alpine Fault is where the Pacific and Australian plates meet in the South Island, while the Hikurangi Subduction Zone is where the same plates collide under Wairarapa and the North Island’s east coast.
GNS Science earthquake geologist Kate Clark, who has been involved in many research projects looking at Wairarapa’s geology, said the plates are currently tightly locked together.
“Eventually, that stickiness will be released by a large earthquake,” Clark said.
“When it comes to Wairarapa, our questions more revolve around, when you have these big earthquakes, does it also rupture other faults through Wairarapa?”
Work looking at the northern South Island suggests large earthquakes from the subduction zone happen every 500 years.
Even though it’s about 500 years since the last big shake, Clark doesn’t believe there’s cause for major panic.
“I wouldn’t call it overdue, but I do think we need to have awareness of it.”
Clark said there were a number of smaller faults running through Wairarapa and along the coast.
“We are particularly looking at the relationship between big earthquakes from the subduction zone and those other faults that are running through the Australian plate, to try and understand how they link together, or if they do, as we don’t really know yet if they really ‘talk’ to each other.”
This particular research will have big implications for Wairarapa, Clark noted.
“There are different earthquake impacts if you’ve just had the subduction zone, versus the subduction zone plus some of these other plate faults running through some of the towns, like Featherston, Masterton, and Carterton,” Clark said.
