Tsunami could catch Auckland off its guard

Auckland could be hit with little or no warning by a southbound tsunami from the Pacific Ocean near Fiji, a scientist has warned.

Dr James Goff, of the National Institute of Water and Atmospheric Research, told a meeting of Civil Defence managers yesterday that Aucklanders needed to be more aware of the dangers of tidal waves in view of the Boxing Day tsunami in South-east Asia.

Devastated Sri Lanka was similar to many places in New Zealand in having a long, narrow stretch of exposed coast, which was open to wave after wave.

Three waves hit Sri Lanka, killing 37,000 people and destroying buildings.

Auckland too could face a tsunami threat caused by earthquake, landslide or volcanic eruption. It could come from three distant areas - South America, the Tonga-Kermadec Trench (about 1000km north-east of Auckland), and the volcanic zone up north near Fiji.

Dr Goff said the area had had a "worryingly quiet" phase since 1.8m waves at Orewa and the port of Auckland in the 1800s. His investigations showed large waves of more than 5m high elsewhere in New Zealand during the 13th century and 15th century, including one at Henderson Bay in the Far North where a wave was 32m above sea level.

The east coast of Great Barrier Island had taken a pasting from tidal waves coming from South America or the Tonga-Kermadec Trench.

He was worried that a historic wave of 5m had come from north of the country rather than the east.

"A wave from near Fiji could be bigger than from other sources because the Hauraki Gulf acts as a funnel.

"If it comes from the north it will affect both east and west coast. Fiji is four hours by tsunami, and we might not know that it's coming."

He said Auckland may not be shielded by Great Barrier and other islands in the Hauraki Gulf.

A wave could continue bouncing around between the coastline and the islands "so it can be worse having an island in front of you."

Dr Goff said using historical geological information in research models promised to answer gaps in the understanding of the tsunami risk.

"Let's get to know this beast."

The Auckland Regional Council said a modelling project should start later this year to help understand which areas would be worst hit in a range of tsunami sizes and sources.

By early next year it was hoped to pass modelling information on to Civil Defence agencies.

ARC civil defence chairman Neil Morrison said the regional civil defence group plan had been approved by the Government and a controller appointed to keep the plan up to speed. An exercise would be held in December.

"We are making good progress, but recent events overseas are a wake-up call not to be complacent.

"Auckland is vulnerable to cyclones, eruptions and major infrastructure failure, and we need more resources and all organisations to think carefully about emergency planning."

Now was a good time for people to check the contents of their "B-ready kit" or view the civil defence information in the Yellow Pages.

For more information about preparing for a disaster visit the website (see link below).