An earthquake struck near Hamner Springs in Canterbury on Thursday morning.
The quake measuring 4.9 on the Richter scale hit just before 9am, 10km north of Hanmer Springs.
GNS Science said people throughout the upper South Island felt the quake, which was fairly shallow at a depth of 12km.
An aftershock, shortly after 9am, measured 4.1 on the Richter scale.
Two earthquakes shook North Island areas on Thursday morning.
A quake measuring 5.8 on the Richter scale was centred 80km northeast of White Island in the Bay of Plenty.
The Taupo region was hit by a 4.7 magnitude tremor just before 10.30am.