GeoNet has reported the quake was a magnitude 6.7, although it was centered at a depth of 193km.
Parliament has been suspended after the quake.
More than 15,000 people have already reported feeling the quake on GeoNet.
GNS Science duty siesmologist Lara Bland warned local residents to expect aftershocks.
Ms Bland said longer, rolling quakes tend to produce fewer aftershocks but there would "certainly" be some coming.
Civil Defence said there is no tsunami threat.