WELLINGTON, July 18 (Xinhua) -- New Zealand studies revealed on Tuesday that Auckland's volcanic past was temperamental, with at one stage several large eruptions happening within 4,000 years, contrasted with thousands of years or more of silence.
Craig Glover, head of Strategy and Planning at Auckland Civil Defence, said they are working with volcanologists to plan the city's response to a volcanic event.
Auckland Council, Civil Defence, and the DEVORA (Determining Volcanic Risk in Auckland) team are investigating new techniques to improve monitoring and warning systems, and on improving Auckland's resilience to minimize disruption in the event of an eruption, Glover said.
Scientists have determined that the Auckland Volcanic Field has a complex and episodic eruption history. The oldest eruption dates back to approximately 200,000 years ago and the youngest only 500 years ago.
According to the studies in the Journal of Volcanology and Geothermal Research and in the Bulletin of Volcanology by a team of researchers from the DEVORA research program, at least half of all the eruptions occurred in only the last 60,000 years -- which is a relatively short time frame and indicates an increase in the rate of eruptions overall.
Graham Leonard, senior scientist at GNS Science who led the research team, said researchers used new data to decode Auckland's volcanic past and understand what sort of volcanic events have occurred and when they happened.
Auckland Volcanic Field has gone quiet for up to 10,000 years in the last 60,000 years, which is quite a long gap, Leonard said, adding that this new research has helped scientists "flesh out an eruption timeline."
Using new techniques, researchers were able to determine that some eruptions in the Auckland Volcanic Field may be interlinked and that the field as a whole, can be either "all on" or "very quiet, sometimes for several millennia," he said.
However, Leonard said the Auckland Volcanic Field is temperamental and a simple likelihood of a future eruption cannot be predicted.
"What our research has revealed is that the past is complex, so we must wait to see what it will do next," he said.