Tsunami risk 'worse than quakes, floods'

Body searchers perform their grim task on Thailand's Phi Phi Island following the Boxing Day tsunami last year. Picture / Brett Phibbs

The risk of a tsunami killing large numbers of people in New Zealand's coastal communities is high, compared with other hazards such as flooding, volcanic eruptions and earthquakes, a new report says.

A serious earthquake on the Wellington Fault was expected to kill 1000 people at most, but a similar frequency one-in-500-years tsunami would kill over 5000 people, said the review of risk and preparedness compiled by GNS Science.

"The risk of multiple tsunami fatalities is high compared to other natural hazards.

"Many regions have intolerable and unacceptable levels of risk at regional level, as well as at individual level," researchers said in the report, released today by Civil Defence Minister Rick Barker.

Many at-risk regions were poorly prepared for a tsunami.

The report on what can be done to improve New Zealand's tsunami-readiness systems was commissioned after last year's Boxing Day tsunami in Asia.

The Indian Ocean catastrophe raised concerns about whether there would be enough warning to New Zealand of a tsunami from the Southern Ocean, the southwest Pacific or one generated close to NZ shores.

Mr Barker was told a scientific review had shown relatively high levels of risk at a national level and in some regions, compared to other natural hazards, where warning systems were in place.

"Tsunami risk has not been paid sufficient attention," the report on preparedness said.

Current warning systems provided barely enough time to issue a simple warning for a tsunami originating off the New Zealand coast.

Warning sirens are already going up on some beaches.

In the Bay of Plenty, the first of 11 sirens that will cover the coast from Waihi Beach to Pukehina has already been installed by district councils, which fast-tracked their plans after the tsunami killed more than 231,000 people around the Indian Ocean's shores.

The sirens - due to be in place by Christmas -- will be tested and a publicity campaign started to tell people how to react in an emergency.

Hugh Cowan, A geological scientist responsible for national hazard monitoring and warning systems has warned that coastal communities at risk of tsunami need to review their planning requirements for low-lying areas.

Dr Cowan led New Zealand scientists in an assessment of tsunami damage in Thailand earlier this year and warned, before today's report was written, that planning requirements for low-lying areas should be reviewed.

Prudent leaders in coastal communities would avoid development in high-risk zones, he said. In some cases low-lying beach suburbs might need to build refuges for people to climb above the waves.

- NZPA