Earthquake Commission funds new research to better understand Auckland's volcanic surges

Tuesday, 24 July 2018

Who will need evacuating if a volcano erupts in Auckland?

Auckland's civil defence managers are to be given high tech help in deciding how many households would need to be evacuated if a volcano erupts.

The Earthquake Commission will fund Massey University's Dr Stuart Mead to lead a project that was part of a $1 million fund announced in February under its 2018 Biennial Research Grants.

Currently, if a volcano threatened to erupt in Auckland, estimates are that about 435,000 may need to be evacuated.

Mead said that figure came from a scenario made years ago and his project would create a model to help emergency managers know who to evacuate based on volcanic surges.

The last eruption within the Auckland volcanic field happened at Rangitoto Island around 500 years ago.

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The biggest threat to life caused by Auckland volcanoes was the 'surge', Mead said.

The surge was a mixture of hot fragmented rock and gas travelling along the ground at around 200 kilometres per hour at the beginning of an eruption, he said.

'The surge affects a smaller area than the ash fall, but inflicts a lot of damage.

Auckland is built on one of the densest volcanic fields in the world, with more than 50 vents dotted around the city.

'We compare it to a bomb blast. It's vital to make sure that people are not in the surge area when an eruption happens.'

Mead said volcanoes gave signals when they were about to erupt.

'In Auckland, current planning means evacuating up to a 5km radius and that could be up to 435,000 people, though the plan also allows for a smaller or larger area to be evacuated if better information is available.

'When we look at research into the history of Auckland volcanoes, we see that some surges have been smaller than the 5km radius.'

Mead said his project would take research that had already been done on volcanic surges and use a computer system to get accurate information about how far the surge would travel and how much damage it would create.

'We are expecting to be able to better define surge damage zones, which could assist in both long-term and evacuation plans,' Mead said.

'Given the potential impact on people, industry, road and air travel and tourism, this information could be very useful.'

Once the information was collated, a 'decision support tool' would be created for emergency managers.

'What we are aiming to show in the model is the likely effects of a surge, and our confidence level in the prediction, so that emergency managers can weigh up the situation and make the best decision,' Mead said.

He said it was a two-year project that would be completed in 2019.

EQC science and education manager Dr Richard Smith said the project was a great example of using scientific research for local action.

'Dr Mead and his team will make a very practical contribution to volcano risk management in New Zealand,' Smith said.

'Getting a better understanding of where and how far a volcanic surge is likely to travel will help Auckland's emergency managers be more effective in managing evacuation.'