With Over Fifty Volcanos in the City Isthmus Auckland Thrives
Auckland was once New Zealand’s hot spot of Volcanoes, boasting approximately 50 within its reasonably small (669 square kilometre) radius.
Auckland city sits between two harbours near the top of the North Island, New Zealand. The Hauraki Gulf on the East coast stretches out to the Pacific Ocean, and the Manukau Harbour on the West coast stretches out to the Tasman Sea toward Australia.
New Zealand is Geologically Young, Auckland’s Volcanoes are Even Younger
The volcanoes are believed to have started forming during the Mesozoic era approximately 120-140 million years ago but the eruptions didn’t actually start till much later. It wasn’t till the Pleistocene era, approximately one million years ago that saw the first eruption with the last one approximately 400 years after that. They were large eruptions in quick succession (geologically speaking) but the volcanoes are considered to be small in comparison to others around the world.
Auckland city is built around the volcanoes but there are a few that are not in-habited. Those that are not inhabited are mostly islands, the most prominent and youngest is Rangitoto, and is believed to have last erupted approximately 600-700 years ago. Rangitoto is now a scenic reserve and is open for public to walk to its summit and look at the lava caves along the way. The island is distinctive and can be seen from any high spot or east coast beach within the city limits, and looks the same from any angle.
Although Rangitoto is the best known volcano in Auckland, there are others of interest to the public as well. Mt Eden and One Tree Hill are both open to the public and have lookout areas at the summit. Most of the volcanoes sit on low lying areas within the city isthmus and gulf.
A Thick Band of Relatively Small Volcanoes Through the Auckland Isthmus
There are no volcanoes north of Northcote-Milford area or south-south west of Hillsborough and Avondale. Thus, when looking at Auckland there is a jumbled band of Volcanoes that cover the eastern and western reaches of Auckland and its inner harbours, although there seems to be no direct line as with the Taupo volcanic zone (TVZ).
Orakei, Panmure basins and Lake Pupuke are now caldera’s or explosion craters that have outlets to the sea and have for many years been considered nice areas to live, with many houses having been build on the edges of their rims, overlooking the water and the crater.
Until recently Mt Wellington was used as an aggregate quarry. In 2004 a Geologist, Bruce Hayward from the University of Auckland pointed out that the volcano, like lots of others in Auckland, was about to be lost, because of housing and industry being build on and around it, he thought New Zealand should be trying to save them. He was correct in his assumption, the mountain has since had houses been built on it but the now unused quarry has not been filled in but may eventually become a lake.
All of Auckland’s volcanos are believed to be extinct as there has been no known, or noted seismic activity for the past few hundred years.
Auckland is the main point of entry to the rest of New Zealand, as aircraft fly across the city many of Auckland’s volcanos can be easily seen between buildings, houses and the Sky tower with Rangitoto being the easiest to distinguish in the Harbour.