After such an incredible sequence of quakes, the problem now was knowing what "normal" was.
Earthquake scientists had "cut their teeth" on the behaviour of quakes from plate boundary faults such as the San Andreas in California and New Zealand's Alpine Fault but knew far less about small crustal quake sequences like this one.
"We know the plate boundary faults' history and behaviour that, say, every 300 years they do this or that. But with this type of event, we don't know what is normal for the Canterbury region," Furlong said.
"We assumed what we had up to September 4 was normal, but it appears it wasn't normal. We don't know what is the background condition that the Earth is now moving towards.
"Each earthquake sequence is unusual, this one both because of its character and observation.
"It's as well-recorded as any of this size has ever been. We are seeing things about it – things that we don't see in any other place.
"It's aspects of this that makes this [sequence] very important to science and why it's hard to be definite about how it's going to behave."
The Rose window & part of the west wall was destroyed in the latest quake.
The Cathedral is now likely to have to be rebuilt from the ground up.
The Anglican Trinity Church.
The oldest stone building in Canterbury - destroyed.
Lyttleton Timeball Station - now completely destroyed.
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