NZ to monitor ocean floor for North Island risk

New Zealand researchers will deploy ocean floor seismometers off the coast near Wellington to gain a better understanding of the lower North Island’s earthquake and tsunami risks.

The project, funded by the Earthquake Commission (EQC) and the Canadian Government, will look at part of the Hikurangi Subduction Zone, where the Pacific Plate is slipping beneath the Australian plate.

Professor Martha Savage says a large portion of the targeted fault area is “locked” compared with further up the east coast and the 20 seismometers will help scientists determine activity levels and the potential for future events.

“This is a big hazard for us because if it goes, it’s going to go fast. The result would be a large and sudden earthquake that could also trigger a tsunami,” Professor Savage says.

The seismometers will be distributed in early 2023 and lifted after 12 months, with data then collected and assessed.

Researchers hope the results will feed into New Zealand’s National Seismic Hazard Model, while the data will also provide information to Canada, which has a similar fault line along its West Coast.

The project, involving researchers from Victoria University of Wellington, GNS Science, University of Ottawa and Dalhousie University, is one of 13 to receive funding through the EQC Biennial Grants program.

EQC has also provided funds for a project that will use Auckland’s fibre network to study small earthquakes, not targeted by existing seismometers, that could help detect volcanic activity under the city.

The Auckland Volcanic Field (AVF) poses a hazard to New Zealand’s largest city, but past eruptions show the challenges involved in predicting events.

“We know there is likely to be an eruption in the AVF sometime in the future and we think that earthquakes might provide some insight into volcanic unrest in the area,” research leader Calum Chamberlain said.

“Being able to accurately monitor seismic signals is essential to forecast the location and timing of an eruption.”

EQC Research Manager Natalie Balfour says the tools tested during the Auckland project, to start in April, will have wider application.

“With many cities having fibre networks and undersea fibre cables running offshore, the techniques and technology the team is developing will be hugely useful for getting a better picture of seismic hazard in and around Aotearoa New Zealand,” she said.

The Biennial Grant program awards a total of $NZ1 million ($934 million) for research into natural hazards and their impacts.