23 Mar 2013

Scientists studying tsunami risk off Kaikoura coast

2:29 pm on 23 March 2013

Scientists are ready to begin analysing data as part of work to assess the risk of a tsunami off the Kaikoura coast.

Marine geologist Joshu Mountjoy says researchers from the National Institute of Water and Atmospheric Research (NIWA) are investigating the head of the Kaikoura canyon where sediment accumulates to gauge its stability and the likelihood of landslides.

Modelling shows that such a landslide could trigger a tsunami sending waves up to 13 metres high into Kaikoura's South Bay with little warning.

Dr Mountjoy says a decade ago, modelling found an area of potentially unstable sediment and researchers want to know if it is still there.

He says once the scale of the sediment is known, scientists can gauge the size of any tsunami and its impact on the South Island town.

Mayor Winston Gray says residents are well aware of the tsunami risk and know to head to high ground in the event of an earthquake, which would be the likely trigger for any landslide.

Mr Gray believes there will be much interest in Kaikoura about what the data shows - and it is not just an issue for locals.

"With the data we'll just be able to work out timeframes, etcetera, and plan around that. There could be a quake anywhere along the east coast; anywhere in the country (a tsunami) could happen.

"So while the canyon does create different possibilities, we all need to be well aware of this issue."

Mr Gray says the town is working to upgrade its preparedness for a tsunami, especially in the wake of the recent Christchurch earthquakes, and the NIWA data will be incorporated into Civil Defence plans.