GNS Science says aftershocks which occurred in Christchurch on Sunday fit the expected aftershock pattern.
A 4.1 magnitude 4.1 quake occurred at 9.35am on Sunday and was followed by a magnitude 4.8 at 5.06pm.
Duty seismologist Caroline Little says there were also four others overnight, measuring magnitude 3.6 at 7.24pm, 3.3 at 8.45pm, 3.4 at 11.29pm and 3.2 at 11.46pm.
She told Morning Report that the larger quakes may have caused some content damage with items falling off shelves, but the damage would be limited as they were all off the coast.
