Alongside a screen which was part of the Selwyn Civil Defence presentation - spokesperson for the Darfield volunteer               Civil Defence unit, Brian Davidson, addresses the crowd.

How To Get Through AF8


A rush to set out more seating was required, when the Darfield Recreation Centre was filled with more than 200 people attending the Selwyn Gets Ready AF8 (Alpine Fault – Magnitude 8) video last Thursday evening, July 5th. While the eventuality of the Alpine Fault rupturing some time soon, is scientifically  indisputable, the video explained the event in an unemotional, informative fashion. The information gleaned from Dr Tom Wilson of the University of Canterbury on the video was easily understandable and presented in a calm, ordered manner. The closing comments of the three civil defence members employed by Selwyn District Council – were the wake-up call. They dealt with the actualities of the event – the intensity of the shaking, the evacuation process, the destruction of infrastructure, the necessity to fend for oneself, and the likely long length of time before assistance would be available. It was sobering stuff!

Darfield’s Brian Davidson, addressed those attending in his role as spokesperson for the local volunteer Civil Defence group. He also called for more members to join them and it was mentioned by the Selwyn speakers that it would be groups like this that would be relied upon for assistance and information in an earthquake.

The video spoke of the very real chance of the Alpine Fault rupturing in the next fifty years. The minimum time it had ever ruptured was after 140 years and the maximum 510. However both these occasions were thousands of years ago and thanks to carbon dating of trapped fibres it can be scientifically proven that for the past few thousand years it has ruptured every 300 years – it is that time now!

Those attending heard that the shaking expected in an AF8 event for Darfield residents would feel of  similar intensity to that in the 2010 quake, but rather than the seconds that that quake lasted, an Alpine Fault event could be up to four minutes long. However the intensity and the time duration is directly related to how much of the fault was to rupture and the direction it set off from.

The Selwyn Civil Defence members asked those present to consider how they would manage without power (the power generation dams etc wouldn’t be functioning) – for possibly many months, how they would manage without fuel (no road/port access). They pointed out that it would be a South Island wide event and being prepared was the only way to get through it.