Volcanoes are exciting. They can erupt spectacularly, throwing molten rock into the air in pyrotechnic displays that are simply stunning. Did you know that one of the most violent eruptions in the world over the last 5,000 years was in New Zealand where Lake Taupō now lies? In fact, 26,000 years ago Taupō exploded in a much greater eruption to devastate much of the central North Island and form an immense hole in the ground that is now filled by Lake Taupo.
We have examples of many types of volcanoes in New Zealand. We have dormant volcanoes (Taranaki, Taupō), active volcanoes (White Island, Mt Ruapehu) and areas where the earth boils and hisses steam as a result of past volcanic activity (Rotorua). Our biggest city – Auckland – is built on a volcanic field.
But what do we really know about volcanoes? Luckily, we have some of the best scientists in the world finding answers. We’ll meet 4 New Zealand scientists who tell us about the volcanoes they have studied and take us on a tour of our local volcanoes and their explosive history.
Meet our 4 scientists
It may come as a surprise that volcanoes don’t have a defined magma chamber. Professor Richard Price at the University of Waikato has been studying Mt Ruapehu and Mt Taranaki, and his research proposes a new model for magma occurrences beneath volcanoes – with crystal mushes and percolating magma but no defined magma chamber.
Dr Darren Gravley at The University of Canterbury has discovered 2 massive caldera eruptions that occurred within just days of each other. One of these eruptions formed Lake Rotorua. Ōhakuri exploded only 30 kilometres away and just days later. This is a remarkable finding. Normally these large caldera eruptions happen on average only every 50,000 years. So why were these events so closely linked? Is this event special to New Zealand? Could it happen again?
Dr Jan Lindsay works at The University of Auckland. Her job is to predict where and when an eruption could occur in Auckland – and what we could do if it did. Her science could save the lives and protect the businesses of thousands of people. Some would say that the developers in Auckland got it very wrong. The country’s biggest city, home to more than 1.3 million people, is built on an active volcanic zone. Unlike Taupō, which straddles an area where two tectonic plates are colliding, Auckland city sits on a volcanic field. This hot spot throws up a new volcano every couple of thousand years. While the eruptions are smaller than those at Taupō, they could happen at any time right in someone’s backyard.
Helping and supporting this research is Dr Phil Shane at The University of Auckland. He looks at rock core samples – drilled sections from the bottom of lakes and swamps that preserve the geological history. Dr Shane can look back into the past, up to 60,000 years ago or more, and see what was happening in Auckland and in New Zealand. He can track which volcano exploded, when and how violently.
Explore the Volcanoes context to understand our past and help us prepare for a future living with active volcanoes.