Rangitoto older than originally thought

Rangitoto older than originally thought

New research has revealed Auckland's iconic Rangitoto Island may be thousands of years older than originally thought.

The volcano was believed to have formed in the Hauraki Gulf when it erupted 500 years ago, but now scientists say it could be up to 6000 years old, and the island could be covering a group of smaller volcanoes.

Rangitoto is an Auckland icon and had always been accepted as the region's youngest volcano.

"Rangitoto might have started erupting much earlier than we expected," says Auckland University Associate Professor Phil Shane.

"The new work suggests that the volcano might have been built up from numerous eruptions, perhaps near continuous activity or intermittent activity, over hundreds of thousands of years rather than just one big burst."

The revelations come after researchers, including Assoc Prof Shane, drilled 150 metres into the volcano's surface last year. They found not only did Rangitoto form thousands of years ago, but it's possible a cluster of smaller volcanoes are buried beneath it.

Assoc Prof Shane says while any volcanic activity would be disruptive to Auckland, there's no reason to panic.

"The eruptions are not necessarily explosive and devastating from a human point of view, but of course future eruptions would affect transport and people's everyday life and just may mean that we have to learn to adapt to live with future activity."

And while an eruption might be hundreds of years away, Assoc Prof Shane isn't ruling out something happening much earlier.