Four earthquakes were felt across the country overnight on Tuesday - the biggest a 4.8 magnitude tremor north of Te Anau at 12.46am.
The quake had a depth of 120 km and was centred 50 km north-west of Te Anau.
There were two quakes in Canterbury just before 3am.
The first was a 3.3 magnitude tremor at 2.50am centred 10 km east of Christchurch, at a depth of 9 km.
The second, a 3.7 magnitude tremor at 2.57am, was centred 10 km southwest of Christchurch, also at a depth of 9 km.
In the North Island, a 3.3 magnitude tremor at 4.43am was centred within 5 km of Tokomaru Bay, with a depth of 15 km.