Reading the rock

''As best we can judge from geology and historic activity, volcanoes or vents that are as cheek by jowl as Red Crater on Tongariro and Ngauruhoe absolutely don't talk to each other.''

Then there’s Taupo¯ , which is prone to enormous rages and damage, but also capable of great kindness. And that’s the challenge for forensic vulcanology – while each volcano has its characteristics, every eruption is to an extent unique. While the Oruanui eruption was massive, the smallest of Taupo¯ ’s 28 eruptions since was small enough that Wilson would have been happy to watch it with a gin and tonic in a deserted lakeside bar.

It’s his job to read the history in the rock and try to understand common factors linking vastly different events. And then to work out what impact those eruptions would have if they happened today, to aid decisions about safe building zones, or evacuation plans.

The holy grail is to marry the gung ho and cunning coward schools of thought, to better understand how a volcano is behaving in real time. With improving technology, forensic vulcanologists can measure how rock travelled to the surface in past eruptions, and how long it took, so if monitoring picks up similar magma movement in the future they know to expect an eruption.

‘‘The challenge is are we going to see a little dome built up in the lake, or a big explosive eruption? We don’t yet know what we don’t know.’’

With earthquakes shaking Mexico, an eruption forcing mass evacuations in Vanuatu and Bali’s Agung volcano threatening to blow, the Pacific Ring of Fire seems tetchy. However, Wilson says that’s no clear predictor of eruptions here.

‘‘As best we can judge from geology and historic activity, volcanoes or vents that are as cheek by jowl as Red Crater on Tongariro and Ngauruhoe absolutely don’t talk to each other. They’re like two sniffy neighbours glaring at each other over the fence.’’

Wilson doesn’t have a cellphone – he purloined his wife Kate’s this week to be available to media. He likes being away from things, he says.

He still gets out to ‘‘hit rock’’, just not as often. His ‘‘ageing carcass’’ makes the 38km day hike to his Yellowstone research deposit less realistic, but he can still direct fit young students.

It’s an all-consuming passion and profession, but he’s never reluctant to go to work and he’s never lost the joy of discovery that comes with finding a hidden corner of a deposit you’ve spent 30 weeks studying, and seeing something that blows your mind.

And now he’s leading an $8.2m study into the risk of another super-eruption in New Zealand, he’s unlikely to find time to tidy that office any time soon.