Scientists studying how long it might take to evacuate people from Auckland ahead of a future eruption of the areas volcanic field have found it could take around two days in one possible scenario.

Auckland Volcanic Field eruptions are usually in a new location each time, with 53 currently identified volcanic centres responsible for some of the cones and lakes around the city.

“As the magma that feeds a new volcano gets closer to the surface, it becomes easier for scientists to estimate where the new eruption will occur,” Auckland Emergency Management Principal Science Adviser Angela Doherty said.

“But there would be a fine balance between waiting for clarity and leaving enough time for everyone to evacuate safely.”

Auckland’s residential suburban areas would require the largest and longest evacuations.

Up to 320,000 residents may need to evacuate when the location of the new eruption is fairly well understood, which could take up to 49 hours to complete, the research says. When the location of the impacted areas is less certain both of those numbers increase.

“An eruption is unlikely in our lifetime but we know an eruption will occur in the Auckland Volcanic Field in the future,” University of Auckland PhD candidate and lead researcher Alec Wild says. “What’s difficult is that we don’t know where the next eruption is going to be.”

The research is part of the Determining Volcanic Risk in Auckland (DEVORA) program, which involves a team of scientists from around the world working in partnership with Auckland Emergency Management, Auckland Council and the Earthquake Commission.

Research results from Mr Wild and co-authors was published recently in the Journal of Geothermal and Volcanology Research.

The next step in the research will involve developing maps and tools to support decision-making during volcanic crises, while it will also help refine regional emergency management and evacuation planning for eruptions.