Having grown up in Wellington I am quite used to experiencing earthquakes, once they start I actually find the anticipation of what will happen next quite exciting.
Recent quakes felt in Wanaka have been silent, rolling and long lasting, quite different from the usual rumble and hard shake. Local builders involved in recent repair work comment how modern polymer modified external render on polystyrene has held up much better than the traditional 20mm cement render, so I guess there is one positive for the modern ‘chilly bin’ houses that are spreading around suburbia.
I read with interest that an international group of scientists are looking at drilling 4 to 5km into the South Island Alpine fault to monitor the activity of rock movement prior to an earthquake. The fault generally moves about 27mm a year but the group believe there is a good chance of a major rupture in the next 20 years. They say major quakes can rupture up to 8m and have typically occurred every 200 – 400 years with the last in the alps being in 1717.
The local engineers get a bit of a hard time about some of the engineering that goes into local buildings, but there is a reason for it, how much damage do you want to risk on your investment?