Alpine Fault Workshop in Dunedin
Alpine Fault Workshop in Dunedin
Representatives of fifty organisations from throughout Otago met in Dunedin today to participate in planning for the first week of response to a major earthquake on the Alpine Fault.
The workshop was part of the Project AF8 partnership between all of the emergency management groups in the South Island in preparation for an eventual Alpine Fault earthquake. Project AF8 is supported by the Universities of Otago and Canterbury, and GNS Science, and is funded by the Ministry of Civil Defence & Emergency Management.
Chris Hawker, Regional Manager Emergency Management Otago, said that a rupture of the Alpine Fault would create major challenges for Otago, including significant damage to buildings and infrastructure. “Based on modelling, the more mountainous western parts of the region closer to the Alpine Fault are likely to experience the most impact. Many communities will be isolated and without essential services for days or potentially weeks due to shaking, liquefaction, and landslides.” Mr Hawker said.
Project AF8 Programme Manager Jon Mitchell said planning to support Queenstown Lakes and Central Otago communities had been a focus of much of today’s planning, while also recognising issues coastal Otago would face. “There are countless aspects to this scenario,” Mr Mitchell said.
Workshop discussions revolved around identifying potential impacts, community needs and priorities, and planning to provide and coordinate relief, reconnaissance, public information, evacuations, and ongoing support to affected areas.
“Meeting the needs of both residents and visitors in the event of a major earthquake requires extensive pre-planning and coordination between emergency services, local authorities, government agencies, NGOs, critical infrastructure providers, businesses, communities, scientists, and the media. Every region in the South Island would be affected by an Alpine Fault earthquake with most damage being in areas close to the fault, especially the West Coast.”
Science leader for Project AF8, Dr. Caroline Orchiston, University of Otago, said Project AF8 was informed by the best current science on the nature and impact of Alpine Fault earthquakes. “We know that the Alpine Fault ruptures on a very regular basis, approximately every 300 years, with the most recent rupture in 1717 – 300 years ago. There is a predicted 30% - 50% likelihood of an Alpine Earthquake in the next 50 years and an 85% likelihood in the next 100 years.
Dr Orchiston said the scenario being used for the project was based on a 400 km section of the Alpine Fault rupturing, generating an earthquake of magnitude 8.2 – that’s around 10 times more powerful than the recent Kaikoura quakes. “In that eventuality, the shaking could continue for up to 5 minutes, causing damage, landslides, and liquefaction hundreds of kilometers from the quake’s epicenter. Both Dunedin and Christchurch are likely to experience shaking and liquefaction in low-lying areas,” Dr. Orchiston said.
Regional planning workshops are being held in each South Island region and once they are completed in April, a coordinated South Island Alpine Fault Earthquake (SAFER) Plan will be developed. The intention is that it will be completed and exercised by the middle of 2018.