Reading the rock
Colin Wilson
Where most drivers see unsightly roadworks, Colin Wilson sees a story. Pass a bearded bloke staring at a fresh road-cut in the Taupo¯ region and chances are it will be Wilson, reading the rock.
Like any ancient inscription, you have to learn to decipher its secrets. But once you’ve mastered the code, the rock that was once molten magma in the belly of a volcano can reveal much about the eruption that forced it to the surface.
‘‘If you know what to look for, and you start to understand the language, they start to tell you all these detailed stories,’’ the veteran vulcanologist says.
In Wilson’s shambolic Victoria University office – behind the tape measures, hard hat and chocolate banana cake, next to the blue fish bins labelled ‘‘Yellowstone’’ – is a soccer ball-sized lump of rock.
There’s a whole PhD in this, Wilson explains. The black and tawny layers are different types of magma – that one’s come up from about 80km deep. The composition of the shiny white feldspar crystals and tiny black flecks of iron oxides can reveal the temperature at which they were created. This, says Wilson, is CSI Taupo¯ .
There are two schools of vulcanologist: the gung-ho types who run toward rumbling volcanos, making observations through ash clouds and fire fountains and occasionally getting killed. And the forensic vulcanologists, who analyse magma thrown up sometimes millions of years ago, to try to understand the patterns of past eruptions and how they might predict future behaviour.
‘‘It’s like someone observing a fight and rushing in to help, and getting knifed or shot for their pains. And then there’s the cold-blooded types that wait till the action’s finished.’’
Wilson is, he says, one of the ‘‘cunning cowards’’. Often by necessity – the supereruptions he specialises in are so monstrous, if you’re close enough to see the vent and lava plume, you will die. The Oruanui eruption that created the collapsed crater beneath Lake Taupo¯ 27,000 years ago was so explosive it spewed pumice dust and ash as far away as the Chatham Islands and Antarctica.
While Wilson has studied volcanoes around the world, including in Yellowstone National Park, Alaska, on Santorini and the Kermadecs, Taupo¯ is his specialty. He’s a details guy – knowing a lot about one thing suits his temperament. He played chess for a while, but doesn’t enjoy losing. The beauty of research, he says, is that the only limit is your own brain.
Abottle of English staple worcestershire sauce on Wilson’s desk provides a clue to his own origins. Brought up near Oxford, he came to vulcanology by chance. Just before his Imperial College London entrance interview, an Icelandic volcano blew right next to a major fishing port. The photos were spectacular. So when the interviewers asked about his interests, he said volcanoes.
They paired him with world-renowned vulcanologist George Walker, who in 1978 emigrated to New Zealand on a Cook Research Fellowship. Wilson followed, and eventually stayed, working for GNS, Auckland University and – since 2009 – Victoria University. He was this week awarded the Royal Society’s Rutherford Medal for research.
At 61, Wilson can recognise 50-100 volcanoes from a photo. Each has its own personality, from its shape and temperament to the kinds of rock it throws up.
People often think of volcanoes as being like a rugby ball – being pumped up and pumped up until they inevitably burst. It’s a bad analogy, Wilson says. The Oruanui eruption was a stop-start affair. Volcanos can be very finely tuned – like seeing Gerry Brownlee in a tutu doing ballet, he says. (He likes to conjure imagery he knows his students will remember.)
There are the Winston Peters characters of the volcano world, such as Papua New Guinea’s Rabaul, Wilson says.
‘‘It looked like drums, trumpets and an eruption on the way in 1982/83, then it went back to sleep. Then it erupted with very little warning in 1994. This is what personalities are like – Winston could say I’m going to announce it tonight, at 6 o’clock, then he suddenly says ‘No, I haven’t made my mind up yet, I’ll let you know tomorrow’.’’
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.