From The Hip

So now what?

This video excerpt from a 1996 Inside New Zealand special on earthquakes has been doing the rounds on Twitter today. While interesting viewing to those who haven’t seen it, I think a couple of things should be kept in mind.

First, I think people should be very careful not to make assumptions and draw conclusions about what happen in the September 4th and subsequent catastrophic February 22nd earthquakes, before any sort of factual information has been gathered on the cause of the destruction around the city, especially with regards to the CTV and Pine Gould Corporation buildings.

Second, no one should be particularly surprised at the information revealed. I vividly remember seeing this when it screened in 1996. I remember the focus on the high susceptibility to liquefaction particularly in the east of the city. I remember the claim of an earthquake potential of magnitude 8 on the Alpine Fault. The risks have long been known, and still exist today. The conclusion some are coming to from watching this is, given these risks were known, things should have been done totally differently. Hindsight is indeed 20/20.

The reality is there were processes in place to mitigate these risks. Strengthening work saved many buildings and lives in the city. New construction and infrastructure work was being done to a standard which would stand up to these reasonable known risks.

So now what? We still face the same risks we did in 1996 with regards to large earthquakes on faults relatively close to the city. What do we do differently? Do we go out and rip down every building which doesn’t meet 100% code within two years? Too slow? Ok, lets reduce that to a year. Now what if the Alpine Fault went tomorrow? People would be up in arms because things still moved too slowly. What if the city was retrofitted in a year, and the Alpine Fault didn’t go for another 200 years? People would see the haste of the massive cost outlay as unnecessary and pressured.

Risk is inherently hard to quantify. I sure as hell didn’t expect to be woken at 4:35 AM on the 4th of September to a massive earthquake, nor see the things I saw on the 22nd of February. You can only do your best with the information you have at the time, and work within the practicalities you face.

Layton