One year to the day since the 7.1 magnitude earthquake in Canterbury, GNS Science says increased seismic activity could continue in the region for several years.
There have been three major earthquakes and more than 7000 aftershocks since 4 September 2010.
GNS seismologist John Ristau says it is important to remember that before the September quake it was rare to feel an earthquake in Canterbury.
Mr Ristau says the likelihood of an aftershock over magnitude 5 in the next twelve months is about 80%.
However he says the longer the region goes without a significant quake, the less likely it becomes that one will hit.
