Auckland’s explosive past uncovered
Scientists are filling in the gaps of Auckland’s temperamental volcanic past.
In studies published this month, a team of researchers from Determining Volcanic Risk in Auckland found the Super City has had a complex and episodic eruption history.
The oldest eruption, Pupuke, was about 200,000 years ago, while the most recent, Rangitoto, was a mere 500 years ago.
However, the time in between eruptions was inconsistent and unpredictable, the scientists found.
Somewhat alarmingly, more than half of Auckland’s total eruptions have been in the past 60,000 years.
The researchers said that indicated the rate of eruptions has been increasing, although there had also been quiet periods of up to 10,000 years.
GNS Science senior scientist Dr Graham Leonard, who led the research team, said some eruptions flared up after what was, ‘‘geologically speaking’’, a short period of time. ‘‘For example, there can be six to 10 volcanoes erupting within a 4000-year timeframe.
‘‘On the other hand, the volcanic field has also gone quiet for up to 10,000 years in the last 60,000 years, which is quite a long gap.’’
Leonard said the new research was ‘‘exciting’’ because ‘‘it has allowed us to further define when eruptions have occurred which has helped us flesh out an eruption timeline’’.
Craig Glover, head of strategy and Planning at Auckland Civil Defence, said the research showed that Auckland’s volcanic field was ‘‘unpredictable.
‘‘We all need to be prepared and while it might seem daunting, planning for a volcanic eruption is no different to planning for any other disaster – have a talk with your loved ones and make a plan.’’
Natalia Deligne from GNS Science previously said researchers had ‘‘no idea’’ when, or where, Auckland’s next eruption would be.
They were ‘‘pretty confident’’ there would be another eruption, but when it would come was anyone’s guess, she said.
Auckland’s volcanic field is the most densely populated field of its type in the world.
In March, GNS Science released a report saying the region’s next eruption would likely come from a volcano that doesn’t exist yet.
One of many explosion craters remaining in the Auckland volcanic field.