Within 15 minutes more than 7600 people had reported feeling it.
Christchurch was jolted by a magnitude 4.3 earthquake this lunchtime.
An earthquake aftershock measuring five-point-one on the Richter Scale hit Christchurch this morning, just after six o'clock.
Two earthquake scientists say the chance of a magnitude six aftershock hitting the Canterbury region is decreasing day by day and is now unlikely. A Victoria University professor in geophysics and a GNS seismologist have put into perspective the weekend's devastating earthquake at a lecture in Wellington.
Mansonry fence toppled by the magnitude 7.1 earthquake in Christchurch on Saturday 4-9-2010.
Shop parapet toppled in the magnitude 7 earthquake in Christchurch on Saturday 4-9-2010.
Shop parapet toppled in the magnitude 7 earthquake in Christchurch on Saturday 4-9-2010.
Glass windows shattered in the magnitude 7 earthquake in Christchurch on Saturday 4-9-2010.
Chimney stack toppled in the magnitude 7 earthquake in Christchurch on Saturday 4-9-2010.
Mansonry fence toppled by the magnitude 7.1 earthquake in Christchurch on Saturday 4-9-2010.
Glass windows shattered in the magnitude 7 earthquake in Christchurch on Saturday 4-9-2010.
Shop parapet toppled in the magnitude 7 earthquake in Christchurch on Saturday 4-9-2010.
Shop parapet toppled in the magnitude 7 earthquake in Christchurch on Saturday 4-9-2010.
Shop parapet toppled in the magnitude 7 earthquake in Christchurch on Saturday 4-9-2010.
Collapsed roof and parapet following the magnitude 7.1 earthquake in Christchurch on Saturday 4-9-2010.
Trailer load of fallen debris following the magnitude 7 earthquake in Christchurch on Saturday 4-9-2010.
Collapsed roof and parapet following the magnitude 7.1 earthquake in Christchurch on Saturday 4-9-2010.
Masonry debris on the ground following the magnitude 7.1 earthquake in Christchurch on Saturday 4-9-2010.
Roof of this building collapsed during the magnitude 7.1 earthquake in Christchurch on Saturday 4-9-2010.
This shop lost its side wall when the magnitude 7.1 earthquake struck Christchurch on 4 September 2010.
Tourists checking out destruction caused by the magnitude 7 earthquake in Christchurch on Saturday 4-9-2010.
Collapsed roof and parapet following the magnitude 7.1 earthquake in Christchurch on Saturday 4-9-2010.
Collapsed roof and parapet following the magnitude 7.1 earthquake in Christchurch on Saturday 4-9-2010.
This shop lost its side wall when the magnitude 7.1 earthquake struck Christchurch on 4 September 2010.
Cracked parapet caused by the magnitude 7.1 earthquake in Christchurch on Saturday 4-9-2010.
Cracked parapet caused by the magnitude 7.1 earthquake in Christchurch on Saturday 4-9-2010.
Police cordoned off roads to the CBD following the magnitude 7 earthquake in Christchurch on Saturday 4-9-2010.
Police cordoned off roads to the CBD following the magnitude 7 earthquake in Christchurch on Saturday 4-9-2010.
Police cordoned off roads to the CBD following the magnitude 7 earthquake in Christchurch on Saturday 4-9-2010.
Facade and roof of this building collapsed during the magnitude 7.1 earthquake in Christchurch on Saturday 4-9-2010.