For the first time, researchers are digging into the seismic history surrounding the Taupō Fault Belt to unlock insights into how the ‘twin threats’ of earthquakes and volcanoes could collide and impact communities and infrastructure in the region.

While Taupō is better known for its volcanic activity, it is also exceptionally seismically active compared to many other volcanic regions around the world, explains lead researcher Dr James Muirhead (University of Auckland) whose work is funded through the Natural Hazards Commission Toka Tū Ake (NHC).

“The Taupō supervolcano sits in the heart of central North Island, a land actively stretching and pulling apart. This geological tension creates fault lines that spark earthquakes,” explains Dr. Muirhead.

“These earthquakes can shake up molten rock (magma) deep underground, making it more mobile and explosive. As the magma rises, it can also unlock and trigger fault lines, leading to earthquakes. It could be a dramatic feedback loop of seismic and volcanic activity.”

The region’s dynamic activity has long been a perfect subject for study. However, a massive eruption 1,800 years ago has left much of the area’s geological history buried under thick volcanic deposits.

“This massive eruption blanketed the land with metres of ash and pumice, making it nearly impossible to track earlier earthquakes in the soil,” says Dr. Muirhead. “What we’re left with is a thick volcanic layer, marking a singular moment in time.”

To get around this, Dr Muirhead and his team are using ground penetrating radar (GPR) technology – essentially an x-ray for the earth—to locate areas where volcanic layers are thinner. In these regions, they’ll dig deep trenches to uncover and study the soil layers, revealing evidence of past earthquakes and volcanic eruptions.

“This groundbreaking research will let us peer back into a 25,500-year history of earthquakes along the Taupō Fault Belt,” he says.

By analysing the sequence of volcanic deposits and the displaced sediment layers caused by earthquakes, the team can estimate the magnitude and timing of past events—providing an unprecedented glimpse into the region’s seismic and volcanic activity.

Dr Jo Horrocks, NHC Chief Research and Resilience Officer, highlights the broader significance of this work: “Natural hazards rarely occur in isolation. This research will shed light on how often earthquakes and volcanic eruptions occur together, and the potential scale of these events. If a large earthquake strikes, should we brace for an eruption? Or could a series of smaller tremors signal an impending eruption? Understanding these patterns will help communities and emergency planners prepare impact of future events.”

Additionally, the research will offer valuable insights into fault lines, helping guide land-use planning in the region. “By knowing where the largest faults lie, we can better safeguard communities and critical infrastructure from earthquake damage,” adds Jo.

This project is funded through an NHC Biennial grant, which supports early to mid-career researchers working on projects to bolster New Zealand’s resilience to natural hazards. NHC’s next round of Biennial research funding opens in May 2025. It is being conducted in collaboration with researchers from GNS Science and Victoria University of Wellington.

Taupō supervolcano facts:

• A volcano is a supervolcano if it is capable of eruptions volumes of lava, pyroclastic fragments, and volcanic ash exceeding 1,000 cubic kilometres.
• Other characteristics include eruption columns that reach more than 25 kilometres into the stratosphere and having ash deposits that can be carried across the planet by wind
• Taupō is one of 20-40 supervolcanoes on earth, and is NZ’s only supervolcano
• Taupō volcano has erupted 29 times in the last 26,000 years, with the most recent major eruption occurring around 1,800 years ago
• This eruption is the most violet eruption known in the world in the last 5000 years
• Taupō volcano is still considered active, with evidence of ongoing geothermal activity and ground deformation
• While the probability of a future eruption is low, the potential for significant unrest and impacts on New Zealand remains
• Taupō also frequently experiences earthquakes, with the latest swarm of more than 50 earthquakes recorded in the area overnight on 31 January 2025. The last significant earthquake was a magnitude 5.6 in November 2022.

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