Life won't stop in an eruption

02:26, Apr 18 2014
Rangitoto Island
BE PREPARED: Rangitoto Island was the last volcanic eruption, about 600 years ago.

If a volcano erupts in Auckland, there's a good chance you'll still have to go to work, experts say.

Hot magma and ash may rain down, but those outside a small danger zone should stay put rather than flee the city, they say.

This is because it would take days to evacuate the city's 1.5 million people through just four exit routes, according to Auckland University research published in the Journal of Applied Volcanology.

Most residents could potentially stay put, carry on working and maybe even enjoy the show.

Auckland University vulcanologist Jan Lindsay said the danger would depend on where the eruption occurred.

"If it pops up in the harbour it could be a lovely tourist attraction. However, imagine if it happens on Queen St. It's a totally different scenario."


In a more explosive eruption there might be clouds of hot ash and gas travelling 4km out from the volcano, but the eruption would still be small when compared with larger eruptions elsewhere.

"Life could almost continue as normal. There is no need to move everyone out of Auckland because it could be a little area within 5 or 6 kms. 

"Ash will be a nuisance but we will learn to live with the volcano."

An active volcanic field underneath our biggest city means an eruption could occur anywhere, including Rangitoto Island, as depicted in Auckland Museum's interactive exhibition and the 2010 TV movie Eruption, which both show terrifying consequences.

The worst-case scenario would be an eruption just south of Mt Eden during the working day, Lindsay said. In that instance, about 500,000 people would need to evacuate the inner city. 

Residents would be likely to receive a warning period as the ground started to rumble.

"It might be just one or two weeks' warning. It may even be shorter than a week."

Evacuations could be staggered from the high-risk zone if there was a reasonable warning, she said.

Affected Aucklanders would move into evacuation centres or with friends in other parts of the city.

An Auckland eruption occurs once every 1000 years on average. Rangitoto Island was the last volcanic eruption, about 600 years ago.

Auckland Civil Defence controller Clive Manley said evacuating the whole of Auckland would cause more issues than it solved due to road congestion.

Auckland was lucky that most volcano eruptions had  been small and short-lived, he said.

Residents must be prepared in case an eruption strikes near their home or workplace. People should have a plan, keep emergency supplies at home and know what to take if leaving in a hurry, he said.

Fairfax Media