Not that far... On whose scale?
By the sound of your post you seem to think Auckland and Christchurch are next door neighbours.
There is aprox 450 miles between Auckland and New Zealand and it is on a different island (South Island)
Auckland isnt free from earthquakes, as isnt the UK - I agree that the UK doesnt sit apon the 'Pacific 'ring of Fire' fault line, but if a disaster is going to strike, it's really just a role of the die to where its going to strike.