There have been a number aftershocks today, including a 6.1 magnitude quake 140km east of Te Araroa at 1.16 this afternoon, at a depth of 33 kilometres.
GNS seismologist Dr Matt Gerstenberger says the shakes are normal.
Dr Gerstenberger says it's not unusual to have a large number of four, five and six magnitude aftershocks following a big earthquake.