Canterbury Earthquake

Canterbury earthquake and aftershocks
(Image MARK CORNELL/The Press)

At 4-35 am on Saturday September 4, a 7.1 magnitude earthquake struck the Canterbury region of the South island, with the epicentre at Darfield, 40 km west of Christchurch city, and at a depth of 10 km. Though there was extensive damage to buildings and infrastructure in and around Christchurch, there were no deaths.

Contrast this outcome with the 2010 Haiti Earthquake, magnitude 7.0, in which 230,000 people died, 300,000 were injured, 1,000,000 made homeless and 250,000 residences and 30,000 commercial buildings severely damaged.

Why the difference? Well, we were fortunate that the earthquake struck when most people were asleep in their beds. Had it struck at 4-53 pm, as in Haiti, then there would surely have been fatalities resulting from falling debris in the central city. But most importantly, the strict New Zealand building code which requires earthquake resilience, was the major factor differentiating these events. Most of the commercial buildings suffering major damage in Christchurch central city were pre-code (1935). A high proportion of Christchurch residences were damaged to varying degrees, but apart from a few pre-code brick mansions on rural properties, none collapsed.

The cost of repairing the earthquake damage is estimated at NZ$ 4 billion, about 3 % of GDP. Much of this with be covered by insurance, by the Earthquake and War damages fund (which has reserves on the order of $15 billion) and by central government grants to support local business and kick-start reconstruction. The country can handle the repair bill.

The impression here is that emergency services and civil defence system worked like clockwork. Power and water services were restored to most of Canterbury within a couple of days. Now that the aftershocks are subsiding, demolition and repairs are in full swing. It will take a year to complete the reconstruction task.

All-in-all, New Zealanders, and especially Cantabrians, can feel proud of the way we handled this potentially catastrophic event.

For a flyover of the fault line damage, check out

http://www.youtube.com/watch?v=Npqx3WmNkv4