Lessons From La Palma Helps Prepare Auckland For Future Eruption

A volcanic eruption in Auckland will likely result in slow moving rivers of lava flowing through the city, so New Zealand scientists are looking to La Palma for lessons from its 2021 eruption.

“There are very few lava-producing eruptions that have occurred in built-up areas like Auckland, which is why La Palma is such a good example of how lava interacts with buildings and infrastructure,” explains Dr Geoff Kilgour, a volcanologist from GNS Science. He recently led a research trip to La Palma as part of a project funded by the Natural Hazards Commission (NHC) Toka Tū Ake.

“With the type of volcanoes we have in Auckland, we can almost certainly expect to see lava flowing for hundreds of metres to several kilometres from its vent.”

La Palma’s 85-day eruption released over 160 million cubic metres of lava downslope over inhabited areas of the island, at some points reaching 70 metres thick.

“The scale of destruction is hard to imagine. Thick rivers of lava flowed through populated areas towards the sea, burying hundreds of houses. We spoke to Canarians who lost their homes and have had to relocate, and others whose health is suffering because they continue to live in damaged homes they can’t afford to repair.”

Initial damage assessments were made from satellite-based images, but Kilgour says a key lesson from La Palma’s experience is that those remote methods often do not provide enough detail.

“Although it’s convenient for getting a rough idea of the scale of total destruction, it doesn’t pick up on smaller and more nuanced damage.”

Accurate assessments are critical because they dictate safety advice and insurance payouts. Initial damage based on satellite data totalled $1.5 billion NZD, and Canarian officials are only now conducting more detailed ground analysis.

“We see benefits from on-the-ground analysis happening as soon as possible post-eruption, so that people can begin to rebuild their lives,” says Kilgour.

Kilgour also observed how lava ignited fires as it flowed, which will feed into models to predict risk from lava fires in Auckland.

“We expect fires to be a big issue in Auckland, where we have many more timber frame buildings, and our volcanoes produce similarly hot and fluid lava.”

The engineering challenges involved with rebuilding critical infrastructure is similar to what we can expect to see in Auckland and can inform future planning, says Kilgour.

“Layers of cooling, but still very hot lava means nothing heat-sensitive can be built directly on or below ground. Some of the solutions had to be quite savvy, including going back to old Roman techniques for building roads involving limestone, which hardens with heat.”

NHC funded the research to get a better understanding of how lava flows will impact peoples’ homes and infrastructure in New Zealand, says NHC’s Chief Research and Resilience Officer, Dr Jo Horrocks.

“It will help us understand how to better assess damage post-eruption, and inform scenario planning and modelling of future impacts,” says Horrocks, adding that the findings will also be useful for emergency planners and councils.

Although the chances of a major eruption in New Zealand are low – the last time NHC settled claims related to volcanic damage was in 1996 following the Mount Ruapehu eruption – the scale of damage if an eruption occurred in Auckland could be significant.

“As we saw in La Palma, given the monumental impact that a volcanic eruption could have on people and property, it’s important to be prepared.”

Engineering against volcanic damage is difficult, but NHC and others are funding research into how different building materials respond to volcanic impacts such as gas, ash, ballistics, and fires. NHC also supports volcanic risk modelling and scenario planning, as well as public education programmes.

“The most important thing is knowing where to go for information, which is your local council or emergency management office, and taking general preparedness actions like having a go-bag, a back-up supply of food and water, and knowing your neighbours.”

The National Emergency Management Agency’s ‘Get Ready’ website also has extensive information on actions you can take before, during, and after volcanic activity.

Kilgour is currently working on applying his findings to an Auckland context and sharing the information with stakeholders in New Zealand and the Canary Islands.

About the Natural Hazards Commission

The Natural Hazards Commission Toka Tū Ake exists to help New Zealanders prepare for and recover from the impact of natural hazards. One of the ways we do this is by providing natural hazards insurance for homes and residential land. Homeowners have access to our scheme if they have an insurance policy with fire cover. The premium paid to insurers includes a Natural Hazards Insurance Levy, which is the amount homeowners pay for this cover.

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