Leaders optimistic over quakes

Gerry Brownlee. Photo / Sarah Ivey

A one in four risk of another major earthquake is weighing heavily on the minds of Cantabrians - but local leaders are seizing on a much more optimistic outlook as a reason for people to commit to the region.

In the wake of last September's 7.1 magnitude quake, and the 6.3 magnitude quake in February that killed 181 people, scientists yesterday confirmed their view that the probability of another quake of magnitude 6 to 7 in the year ahead was 23 per cent.

The figure relates to the wider Canterbury area where aftershocks have been occurring, with just a 6 per cent chance of another large quake in badly damaged Christchurch City.

Scientists have also revealed they have discovered previously unknown faults in the ground beneath Canterbury and offshore which could generate these large quakes.

The risk may be too much for some in Canterbury - with some residents who fled after the February 22 quake telling the Herald they could not face the thought of going through something like that again.

Long-serving Christchurch City councillor Sue Wells, whose blog this week revealed the one-in-four risk, said it was difficult to know how people would react emotionally. But people should take the figure for what it was worth, she said.

"At the end of the day, we don't know what we don't know. I'm sleeping well at night and if something goes off, it goes off. If that is the final straw for a person ... then everything else has already gone wrong."

Scientists from GNS Science say once the first year has passed, the risk of one in four drops to one in ten for the following year. In the decades ahead, the earthquake hazard for Christchurch "is probably a little bit less than for Wellington", said Dr Matt Gerstenberger.

The building standard for earthquakes in Christchurch would still be less than for Wellington, said Earthquake Recovery Minister Gerry Brownlee.

"The really important thing is that the indications are that as all of this current seismic activity settles down, and inevitably it will, the return incidence appears to be very, very long range."

"New Zealand is a country where you choose your risk. And the factors about risk from geological events here in Canterbury are going to be much better understood in future. The future is bright."

Ms Wells said Christchurch would rebuild as the safest city in the country. "Let's face it, we lost many of the buildings that were most likely to cause us problems."