What would happen if a volcano erupted in Auckland? – In the News

It’s no secret that Auckland sits on a large volcanic field, but new research has modelled what would happen if there was an eruption within the city limits.

Browns Island and Rangitoto in Auckland’s Hauraki Gulf are two of the 50-plus volcanoes in the Auckland Volcanic Field that have erupted in the recent geological past. Photo – Lloyd Homer, GNS Science.

The study, published last week in the Journal of Volcanology and Geothermal Research, considered what could happen during a hypothetical two-month-long period of unrest and eruption near Mangere Bridge.

The researchers from GNS Science, the University of Canterbury and Massey University said that biggest danger from such an eruption would be a pyroclastic surge – a hot mix of gas, ash and other substances that could spread over a five km-wide area.

University of Canterbury’s Associate Professor Tom Wilson told Radio NZ the key thing to keep in mind was “we don’t know where the next eruption is going to come up”.

“There’s a large area around Auckland where’s there’s been over 50 known eruptions in the past, we aren’t sure next one is.”

“Certainly within two kilometres of the eruption vent, probably near total destruction: houses, buildings, any other critical infrastructure is likely to be heavily damaged if not destroyed.”

Early hints of an impending eruption would be through a swarm of earthquakes, the researchers said. “The seismographs around Auckland is our key tool in determining when we start seeing earthquakes like that and if we’re starting to see any rise in that magma,” Dr Wilson told Newshub.

“Maybe once we had detection that there’s been magma on the move, we might have as little as a few hours, all the way through to days to weeks to even months.”

The researchers worked with local lines company Vector to model how such an eruption might affect key infrastructure. GNS Science’s Dr Natalia Deligne said under the scenario, some residents could experience rolling outages from anywhere between a month to a year or more.

Read more about the study on Scimex.org.

The study has been covered by local media, including:

Radio NZ: What would happen if an Auckland volcano erupted
NZ Herald: Scientists plot the destruction that a volcanic eruption in Auckland could cause
Stuff.co.nz: Auckland’s next big eruption likely to come from a volcano that doesn’t yet exist, scientists say
Newshub: Volcanic eruption: How would Auckland cope if one blew?