Big probability of sizeable quake over next 12 months

10:20 pm on 29 September 2012

GNS Science says there is a 72% probability of earthquakes of magnitude 5 and 5.4 in Christchurch over the next 12 months.

It also says there is 31% probability of a 5.5 to 5.9 quake in wider Christchurch over the same period.

It calculates the risk of a quake over 6.5% at only 3%.

The principal scientist at GNS Science in Wellington, Martin Reyners, says the risks are typical of the sequence of aftershocks experienced in Canterbury.

Mr Reyner says the impact of future quakes depends on where they are located and how shallow they are.

Christchurch has had 58 earthquakes over magnitude 5 since the first big quake to hit the region on 4 September 2010.