Auckland quake risk vexes insurers

Mount Hobson in Remuera. Photo / Martin Sykes

Auckland's earthquake risk is still unknown and this is of concern to overseas backers of insurance companies, the Royal Commission of Inquiry into the Canterbury Earthquakes has heard.

"If what happened in Christchurch happened in Auckland, the country would be bankrupt," Auckland Council civil defence and emergency management hazards manager Dr Marion Irwin told the commission yesterday.

"Offshore, the insurance [companies'] reinsurers are seeing Auckland as the big risk because of the effects if it did happen there."

Councils from around the country have been briefing the commission on issues of earthquake risk in their towns and cities, as the inquiry looks at what change is required after the Canterbury quakes killed 182 people and caused widespread destruction.

Dr Irwin said while Auckland was thought to have a low seismic risk, that was based on one known active fault and another fault that could be active.

The volcanic structures Auckland was built on made it difficult "to see what is down there" and 75 per cent of earthquakes were happening on faults no one knew about, she said.

The Hauraki Gulf region had active faulting "but there's not very much work being done on that". In 2007, quakes off Orewa resulted in thousands of dollars in claims to the Earthquake Commission.

"Now I'm not saying that the [Auckland quake risk] is any worse than it's been couched to be," Dr Irwin said.

"But we do not have enough studies. What I think we need is a real proactive look at what we have got so that we can define our seismic hazard."

A big programme of research was going on into Auckland's volcanoes and "I would like to see something similar around the Hauraki Gulf, in particular, and its flanks".

The research would not come cheap but some of the funding could come from a national level because of Auckland's national significance, Dr Irwin said.

Asked by commission chairman Justice Mark Cooper what the basis was for her comments about reinsurers' concerns, Dr Irwin said they came from discussions with the Earthquake Commission.

Auckland Council building policy spokesman Bob De Leur told the commission the council was waiting for guidance from it on future building code requirements to cope with potential earthquakes.