If you find yourself unsure of how to best prepare for the next Alpine Fault event, rest assured that information is coming to you. Wanaka is on the list of stops during Alpine Fault Magnitude 8’s (AF8) upcoming roadshow. The inaugural tour will deliver public science talks to 12 South Island communities most likely to be affected by an AF8 earthquake; Wanaka’s conversation is scheduled on March 28 at Lake Wanaka Centre.
AF8 scientists Dr Caroline Orchiston and Professor Mark Stirling will deliver a talk about the associated hazard impact of an AF8 in the region with a specific reference to Wanaka. They will also share more detail on the science backing the AF8 project.
“It’s important to remember that the Alpine Fault is just one of the fault lines that can affect Wanaka and surrounds, and it’s just one of the natural hazards people should be aware of and prepare for,” said AF8 programme coordinator Alice Lake-Hammond.
She said the AF8 scenario demonstrates one of the many ways the Alpine Fault may behave. “We can’t predict the next Alpine Fault earthquake or what exact impacts it will have,” said Lake-Hammond. “However, the AF8 Scenario applies GNS Science's Modified Mercalli Intensity Scale (MMI Scale) to help us understand what the potential short- and long-term impacts could be like. It’s a starting point to help us identify what we need to do to be better prepared.”
The AF8 scenario lists Wanaka as “Slightly Damaging,” which is defined on the The MMI Scale as: "Felt by all. People and animals are alarmed, and many run outside. Walking steadily is difficult. Furniture and appliances may move on smooth surfaces, and objects fall from walls and shelves. Glassware and crockery break. Slight non-structural damage to buildings may occur.”
“An Alpine Fault earthquake of magnitude 8 and its proceeding aftershocks will certainly be felt in Wanaka,” said Lake-Hammond. “The shaking may cause some household objects to move, fall and break, which could cause injury. Some people may be frightened and require extra support.”
When asked about effects of an AF8 on this area, Otago Regional Council emergency management officer Trevor Andrews said, “...the ground will shake for over two minutes. This will seem like an eternity and will be terrifying. People will think the world is ending, particularly tourists who don’t know our hazardscape. Remember to drop, cover and hold.”
Lake-Hammond said that road closures will follow the earthquake, particularly the Haast Pass which could remain closed for months. “Depending on the time of year, tourists may be stranded and require assistance. South Island-wide, power supplies will be affected and communications may be difficult for some time afterwards. Communities should be prepared to look after themselves for seven days and expect ongoing disruption to everyday life in the weeks and months following.”
Andrews said Emergency Management Otago is currently developing the local Wanaka Community Response Plan in consultation with the emergency services, Queenstown Lakes District Council, response partners, medical services along with local community leaders. “It should be ready for distribution to households around late April or May. Makarora and Lake Hawea already have their plans and local arrangements in place,” he said.
AF8 is a collaborative effort to save lives by planning and preparing a coordinated South Island-wide response after a major earthquake on the Alpine Fault.
All ages are welcomed to the Wanaka-based talk, and people can register their interest on the Wanaka – AF8 Roadshow: Public Science Talk Facebook page.