Kaikoura alerted to potential risk

The Kaikoura coast is more at risk from a near-shore tsunami, rather than the type of tsunami which hit parts of Asia at the weekend, experts say.

Environment Canterbury and the National Institute of Water and Atmospheric Research earlier this year outlined to the Kaikoura District Council two scenarios - a near-shore earthquake and a submarine landslide of built-up sediment in the Kaikoura canyon.

Several earthquake fault lines run through the Kaikoura district.

Retired Niwa marine geologist Keith Lewis, of Paraparaumu, said a sea canyon close to the coastline at Kaikoura was one area of potential risk because of the build-up of accumulated sediments washed from the land.
An earthquake could tip the sediments into the canyon, which would trigger a tidal wave.

Environment Canterbury hazards analyst Dawn Davidson said if there was a strong earthquake on a nearby active fault, it would generate a tsunami wave that would be 14 to 15 metres above normal sea level when it reached Goose Bay, south of Kaikoura.

Kaikoura Civil Defence officer Mike Kennedy said that after an earthquake in Chile in 1960, Kaikoura had seven hours warning a tsunami was on its way.

A 60 per cent chance of the Alpine fault rupturing in the next 30 years had been estimated. This could generate a Richter 8 scale quake and, as the Hope fault ran off the main fault, Kaikoura would be affected, he said.

- NZPA