Another aftershock was felt at at 9.04 tonight, and was recorded at a magnitude of 3.9.
It was eight kilometres deep and was centred 10 kilometres southeast of Lyttelton.
There was a 3.5 quake at 8.31 tonight, at the same depth, centred in the same place.
Four aftershocks of between three and 4.8 on the Richter scale struck the area between four and five this afternoon.
Three were centred 10 kilometres from Diamond Harbour and the other one was 10 kilometres east of Lyttelton.
