New Zealand Earthquake

(CNN) -- Scientists in New Zealand said there had been less than a one in twenty chance of Tuesday's earthquake being so destructive.
The fatal 6.3 magnitude quake that has damaged much of Christchurch on New Zealand's South Island was actually an aftershock of the 7.1 magnitude earthquake that struck the same area in September last year.
Seismologists for GNS Science had calculated on Monday that there was only a 35% chance of a 5.0 magnitude aftershock hitting the region in the near future, but only a 4% chance of a 6.0 or above aftershock.
http://www.cnn.com/2011/WORLD/asiapcf/02/22/newzealand.seismic.hotspot/index.html?iref=storysearch