Risk of another big quake in Canterbury put at 23%

10:02 pm on 31 May 2011

Government scientists say there is a near one-in-four chance of another large earthquake striking Canterbury in the next year.

GNS Science says there is a 23% chance of a magnitude-6.0 to 7.0

quake striking somewhere in Canterbury, but the risk to Christchurch is no greater than other quake-prone regions such as Wellington and Hawke's Bay.

There have been two serious earthquakes in Canterbury recently - a 7.1-magnitude quake on 4 September last year, followed by the devastating 6.3-magnitude quake on 22 February.

Matthew Gerstenberger from GNS Science says the prediction is based on a widely-used aftershock model considered reliable by seismologists.

He says there is about a 6% risk that a large quake will hit Christchurch city.

Christchurch mayor Bob Parker says although it sounds scary, the figure is actually no worse than GNS Science has been predicting ever since the first quake in September.

Mr Parker says there is nothing new about the risk, but residents should still be prepared with emergency supplies in Christchurch and around the country.

A Christchurch residents association says it is not worried about the forecast.

Cancern chairperson Tom McBrearty says people are more worried about issues such as land remediation and insurance payouts than the possibility of another quake.

MP questions forecast release

A Christchurch MP wants to know why the forecast was first revealed in a blog post by a city councillor.

Sue Wells said on the blog she was told in a meeting with Earthquake Recovery Minister Gerry Brownlee about the GNS prediction.

The Labour MP for Christchurch Central, Brendan Burns, says the way the forecast was reported was distressing for many people and wants to know why the information was not released in a more managed way.

Mr Brownlee could not be reached for comment on Tuesday.