A magnitude 5.5 earthquake shook Christchurch on Sunday night but there have been no reports of damage.
Geonet say the quake, which struck at 8.34pm, was centred 10 kilometres east of Lyttelton Harbour at a depth of 12 kilometres.
Ilam resident Maryke Fordyce says it was very violent, bringing back memories of the 22 February earthquake.
Christchurch emergency services say they have had no calls relating to the quake.
It was centred in a similar area to several tremors that hit in quick succession on Saturday, ranging in magnitude from 3 to 4.8.
