A shallow aftershock measuring 4 on the Richter scale has been felt in Canterbury.
It struck at 9.30pm on Friday and was centred 20 kilometres north of Akaroa at a depth of 2 kilometres.
A 4.2 aftershock was felt in Christchurch just before 5pm on Friday. It was centred 10 kilometres east of the city, and was 7 kilometres deep.
