
A Mt Taranaki eruption could bring the region to a standstill, knock out regional infrastructure and cause up to $16 billion worth of damage, a new study has found.
Researchers across New Zealand undertook a five-year study weaving together volcanic science, dynamic risk modelling, economic analysis and m膩tauranga 膩 iwi to project what would happen if the volcano erupted.
University of Auckland Professor Shane Cronin said the programme began because researchers knew there was a 30-50% chance that Taranaki could erupt in the next 50 years.
鈥淥ur job was to listen to the mounga, study its past behaviour, and start to understand what signs it might give before erupting again.鈥
University of Auckland Professor Shane Cronin.
What have scientists learned?
Analysis of volcanic layers in local caves narrowed down the timeline of previous eruptions from around 70-90 years to around seven to nine years.
The most recent eruption is now confirmed to have occurred in 1790.
Cronin said this level of precision gave scientists a much clearer window into Taranaki鈥檚 eruption history.
鈥淲e鈥檝e now also able for the first time able to see the duration of eruptions. For example, some of the smaller eruptions have lasted for around 2-3 years,鈥 he said.
Researchers developed nine eruption scenarios.
They range in size and duration to show what small, medium, or large eruptions may look like over months.
鈥淭he scenarios were a game-changer,鈥 University of Canterbury Professor Tom Wilson said.
鈥淪uddenly, people could understand how they may be impacted and were starting to think about the things they could do to prepare.鈥
The research revealed how a disruption to the electricity system could cascade through the oil and gas industries, transport networks, and water systems, causing widespread impacts across the region and nation.
鈥淭he risk modelling suggests a Taranaki eruption is a potential regional disaster, it鈥檚 a national energy security challenge, and a potential future economic crisis,鈥 Wilson said.
鈥淭he ripple effects of an eruption go far beyond ash and lahars.
鈥淰olcanic ash can short-circuit power lines, block roads, contaminate water sources, and clog water treatment plants, causing critical infrastructure systems to fail at the exact time they鈥檙e needed most.
鈥淟ahars could also destroy bridges and cut off lifeline services, disrupting transport and access to basic needs like food and water, as well as limiting access to some communities.鈥
University of Canterbury Professor Tom Wilson.
The economic impact of an eruption
Economic modelling predicts losses from a future eruption of Taranaki mounga could be between $12b and $16b, depending on the type, scale, and duration of the event.
The research programme鈥檚 co-lead, Garry McDonald of Market Economics, said a volcanic eruption could bring Taranaki鈥檚 economy to a standstill.
鈥淭aranaki supplies 100% of domestic gas and 20% of New Zealand鈥檚 primary energy,鈥 he said.
鈥淚f gas production halts, it may not be recoverable. Water entering wells could make them unusable or uneconomic to restart, triggering a national energy crisis.鈥
However, targeted investments in alternative forms of energy could significantly reduce losses, McDonald said.
鈥淎n islanded electricity supply for New Plymouth could reduce outage duration by one month and save over $500 million鈥, he said.
鈥淎 backup borehole water supply for South Taranaki could avoid outages for 8,000 plus homes and save more than $600 million.鈥
McDonald said high-value interventions such as alternative power and water supplies could save more than $1.1 billion and boost regional GDP by 17% over two years.
鈥淪pending now to strengthen critical infrastructure could save billions later.
鈥淚t鈥檚 not just a way to ensure people have water and power, it鈥檚 also smart economics.鈥
Researchers developed nine eruption scenarios from small, medium to large for Mt Taranaki. Photo / Clive Wilkinson
Weaving m膩tauranga M膩ori and risk science
The programme worked in partnership with Uri to weave together m膩tauranga M膩ori and Western science.
Bilingual resources, interactive StoryMaps, and w膩nanga created spaces for k艒rero about the mounga鈥檚 past and future.
鈥淵ou can鈥檛 understand volcanic risk in Taranaki without understanding the whakapapa of the mountain, whenua and awa, the k艒rero tuku iho and m膩tauranga held by wh膩nau, hap奴 and iwi who hold ancestral connections to the mounga and have done so for generations,鈥 said Acushla Dee Sciascia of Mapuna Consultants.
This research provided a platform for M膩ori researchers to contribute their voices, leading to richer outputs including monographs, visual exhibitions, and new ways of telling the mounga鈥檚 story.
鈥淭aranaki mounga provides us with so many learnings from its past and how our t奴puna navigated previous volcanic events, and it鈥檚 up to us now to prepare our wh膩nau for the future,鈥 Sciascia said.
鈥淭his programme has laid a foundation. But the real mahi is in how we carry this forward, and how we embed m膩tauranga M膩ori into everyday planning, science, and response.鈥
Cronin said researchers, iwi, and emergency managers came together to ask: 鈥淗ow do we prepare for a future eruption?鈥.
Wilson said researchers know far more now than they did.
鈥淏ut unless our systems evolve to act on that knowledge, the risk remains,鈥 he said.
鈥淓arly investment will save billions, protect lives and livelihoods, and strengthen national resilience. The science supports the investment.鈥
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