Queensland was struck by an earthquake on Saturday, a 5.2 about 20 minutes before our 5.3. The epicentre was 124km Southeast of Townsville at a depth of 10km. Earthquakes are very unusual for Queensland. I certainly never felt any in the 30 or so years of my life spent living there.
I phoned my friend Sarah who lives in Townsville to talk to her about it. She and her husband felt it but were unsure what it was with her husband attributing the shaking to the wind. She thought not and suggested an earthquake. Then it finished and she thought no more about it until my phone call.
How nice it would be to be an earthquake virgin again. Most of our aftershocks are small and do not cause any damage but nevertheless, my fight or flight response kicks in for each one I feel. My self-preservation instinct must be strong. For each aftershock, my heart rate, blood pressure and rate of respiration increases. This response no doubt enabled me to leap out of bed instantly on September 4th at 4.35am even though I was deeply asleep. The secretion of endorphins also eliminated my pain, which I would otherwise have felt from banging my head on the door hard enough for it to bleed. I did not notice this until much later when I felt something sticky trickling down my face.
I know I am suffering from a form of post-traumatic stress disorder but I feel I am coping with it quite well. My adrenaline response kicks in and as soon as I am aware that this is just a small aftershock and that our children are safe and well, I begin to relax again and it probably takes about 15-20minutes for my systems to return to normal. I do not want to prevent my flight or fight response from occurring because I may yet need it. Seismologists say it is not unreasonable for Christchurch to expect another 6+ aftershock.