First detailed mapping of Whakaari White Island to predict future eruptions

GNS Science is making its fourth and final trip to research the volcanic Whakaari and Mayor islands to better predict how large future eruptions might be.

Following the fatal eruption on Whakaari White Island in 2019, which killed 22 people, the crown research institute pleaded guilty to charges that it failed to fully communicate the island's risks.

The data GNS is gathering will be used to create models to see the potential impact of volcanic activity and better understand the risks.

"This is kind of first detailed mapping of the insides of the volcano that we've done," said GNS science senior volcanologist Craig Miller.

The mapping system uses electromagnetic sensors.

"They're kind of a thing that sits on the ocean floor and records earth's magnetic electric fields and allows us to map where electrically conducted fluids are in the earth's crust," Miller said.

"All our research helps build our conceptual model of the volcano, it's kind of like how the plumbing of volcano works, where the magma is and where hydrothermal systems are."

The data collected will help them understand the triggers, hazards and impacts of potential future eruptions. Early findings have revealed a magma reservoir in the northwest of the island.

"It's interesting and knowing the location of that actually helps us improve our monitoring and understanding of events in that area," he said.

The scientists will be at sea for two weeks working on the research programme which is a collaboration led by GNS Science and involving experts from universities, civil defence and emergency management. There are also two geology honours students on board, who are part of the Sir Peter Blake ambassador programme.

"It's exciting to see what high-level scientists do on these voyages, and hopefully where we can be in five to 10 years," said Lottie Stow from the University of Canterbury.

Georgina Dempster from the University of Otago is also excited to be part of the voyage.

"All of their instruments are from the US... without this opportunity, we probably wouldn't get to see it happen," said Dempster.

As well as the electromagnetic sensors, previous voyages have been collecting sediment core samples from near both volcanos to analyse the ash layers.

"All of that helps us build a picture of how many eruptions happened in past, what size those eruptions have been. We hope to model those and try predict what the on-land effects of those eruptions might be," said Miller.

So, scientists and emergency management are better prepared for future eruptions.