On Saturday 4th September 2010, at 4.36am, my partner and I woke to the biggest earthquake we’ve ever experienced. The pre-quake rumble was terrifying. Freight-train-through-your-lounge volume. Then the quake hit. Apparently it lasted forty seconds. To both of us it felt much, much longer. How to get to the kids in time? How to calm their terror, keep them safe? How to stay on our feet until we reached them?

Magnitude: 7.1 on the Richter scale. Depth: 10km (that’s shallow!). Epicentre: 40km west of Christchurch. Effect on our beautiful city: devastation.

Miraculously, no lives were lost; the earthquake struck when Christchurch streets were at their quietest. The clean-up task will take months – possibly years. Many people have lost their homes, many have lost their livelihoods. But we still have each other. Thank God.

On TV, in the newspapers and online, new images and stories are emerging daily of the destruction that’s been wreaked in a mere forty seconds. I’m struggling to comprehend it all. Twisted shop frontages, piles of rubble, torn buildings, silt and water where neither should be . . . it’s unbelievable.  And the most unbelievable thing of all: our home is unscathed. A couple of breakages, a few doors that don’t want to close . . . but seriously, it’s so minimal it’s almost embarrassing. How did this happen? How did our modest 1936 wooden house remain intact?

Five days on and the cracks are beginning to show. In me, not the house. To say I’m feeling fractious is an understatement. My nerves are completely shot. For how long will these freaking after-shocks assault us? For how long will any faint rumble have me freezing, then grabbing the kids and diving for doorjams?

You’ll have to imagine the nervous responses – but for some idea of the way our week has gone in QuakeZone – check out www.christchurchquakemap.co.nz. (Thanks to Gracie for passing it on.) This simulation says it all.