Expert: NZ still unprepared for tsunami 

Source: ONE NewsWarning siren

New Zealand is no more prepared for a major locally-generated tsunami than Samoa, says an expert on tsunami, Dr Willem De Lange, of Waikato University.

There has been a historical reluctance in New Zealand to spend money on 24-hour staffing of a centre to monitor earthquakes and interpret the tsunami risk, he says.

But the level of preparedness is "exactly the same as Samoa" he says.

The government is expected to soon release a report on the civil defence response in New Zealand to the September 29 tsunami, which struck Samoa's south coast, American Samoa and Tonga - after a magnitude 8 earthquake - and killed 183 people there, and after a quake struck Vanuatu.

According to Dr De Lange, there is a 10% to 12% chance of a damaging tsunami hitting New Zealand during the course of a year.

But he says New Zealand's tsunami warning system focuses on long-distance threats when the greatest danger is from an earthquake or sub-marine landslide close to the coast.

Scientists says after the 2004 Boxing Day tsunami which devastated coastal communities around the Indian Ocean that there was no monitoring in New Zealand for "local source" tsunami - waves which take less than an hour to travel to the coast - or "regional source" tsunami which take between one and three hours to arrive.

They warned that even with all the necessary information available local warnings could take 100 minutes to compile and issue.

A further shortcoming is the lack of real-time sea-level data to detect and monitor the tsunami before it reaches the NZ coasts and to monitor its impact as it progressed along the country.

At the time, Civil Defence relied on Dr de Lange at Waikato University and Rob Bell at Niwa.

GNS Science researchers told the government that Japan is able to produce tsunami warnings within three minutes of an earthquake because it has developed 100 pre-computed models of distant-source tsunami, and 100,000 pre-computed models of local-source tsunami.

But Dr de Lange says the New Zealand warning systems cannot cope with a tsunami from a close event, such as the big Fiordland earthquakes earlier this year, to reach other parts of the coastline in 10 to 20 minutes.

In such events, a warning is needed within five minutes of a quake.

It is not really clear who should make the decision to evacuate, how much scientific advice should be taken before a decision was made, and whether confirmation of a tsunami is needed before a warning is issued.

Authorities are faced with triggering sirens every time there is a sizeable quake - with the potential for a lot of false alarms.

"We're in danger of crying wolf too often," he says.

Dr de Lange says a lot of effort is being put into identifying which areas are most at risk on inundation, so that communities can be educated on the risks and how they should react.