The AF8 (Alpine Fault magnitude 8) team are touring the South Island to speak about the likelihood of a large earthquake striking the Alpine Fault. 

Scientific research indicates a 75 per cent probability of an Alpine Fault earthquake occurring in the next 50 years.

There is a four out of five chance it will be a magnitude eight-plus event. 

Scientists and civil defence personnel were in Cromwell to explain the science and inform of how the public can best prepare for a magnitude eight-plus earthquake on the alpine fault. 

Associate professor Caroline Orchiston says Cromwell is, relatively speaking, in a “nice area” if an event of magnitude eight should occur. 

“You will feel it outside and indoors. If it occurs at night, most sleepers will wake, small objects will shift or overturn, and pictures knock against the wall, and some glassware and crockery may break.

“There might be blackouts and communication trouble for a while and supply chain problems for essential goods,” she said.

Associate Professor Caroline Orchiston and Emergency Management advisor Derek Shaw take questions at this week’s AF8 public event in Cromwell

Modelling of the most likely scenario indicates an eight-plus magnitude quake would be manageable in Central Otago, but severe damage would occur on the West Coast and around the Southern Alps. 

“We have to be aware that they’ll be a period that you will need to be conscious of disruption and potential infrastructure damage,” Caroline said. 

Central Otago Emergency Management advisor Derek Shaw stressed the importance of planning to cope with the likely disruptions following a large-magnitude event on the fault.

“The plan doesn’t need to be extensive; it just has to be inclusive.” 

“Everybody in the family needs to contribute to the plan, and that’s right down to the children so they know they contributed and have ownership of the plan,” he said. 

Of the likely outcome for the Clyde Dam, Associate Professor Orchiston said the geotechnical work it takes to build a dam means that they are robust. 

“A lot of work is carried out to maintain dams and test them for all sorts of events. 

“If there was a landslide into Lake Dunstan, it could generate a wave that might overtop the dam. It would be a pretty low probability to happen, and it doesn’t mean the dam will fail,” she said. 

Listen to The Central App’s Brent Harbour talk to AF8 Programme Manager Alice Lake-Hammond on the latest Outlet Podcast for more information.

Find out more about being prepared here.