Revealed: New Zealand's worst-affected areas after an Alpine Fault quake

The worst-affected areas if the Alpine Fault were to rupture have been revealed.

It comes after scientists claimed the Alpine Fault is overdue for an earthquake that could reshape the South Island.

Last year marked the 300th anniversary of the last time it ruptured, moving the south-eastern side about eight metres relative to the north-western side in a matter of seconds.

Scientists expect that the earthquake would be a magnitude 8 and would rupture along the Alpine Fault, rocking the South Island for at least three minutes whilst causing strong shaking throughout the rest of the country. 

The areas likely to be the most severely hit are the West Coast, inland Otago, Fiordland, inland and low-lying coastal parts of Canterbury, and southern parts of Nelson, Tasman and Marlborough. 

The last Alpine Fault quake, which occurred in 1717, measured an approximate magnitude 8.1 - making it about three times stronger than the Kaikoura quake of 2016.

Revealed: New Zealand's worst-affected areas after an Alpine Fault quake
Photo credit: Project AF8

Project Alpine Fault Magnitude 8 (AF8) has modelled the impacts of the potentially devastating earthquake, highlighting the need for coordination between scientists and emergency planners. 

Project AF8 lead scientist Dr Caroline Orchiston says they have developed a fair idea how the rupture would play out given past incidents. 

Recently, the South Island Alpine Fault Earthquake Response (SAFER) framework was completed, which provides a detailed response plan - categorising the priority needs of those hit by the quake. 

It covers things such as the shelter and care of displaced people - including potentially tens of thousands of tourists - and an immediate medical response and the restoration of priority telecommunications.

The focus is specific to meeting the area's needs; in the West Coast, for example, the focus would be evacuating those most in need and getting support to the worst-affected communities. 

Further north in Nelson-Tasman and Marlborough, workshops have focused on preparing to receive displaced people from the more severely affected areas, and acting as starting areas for resources into and out of the West Coast.