Prof Colin Wilson would not be nearly as surprised as the tourists who were hit by a lava bomb from the Kilauea volcano last week.
On July 16, 23 people aboard a sightseeing boat just off the Big Island of Hawaii were injured, several seriously, when a chunk of hot volcanic lava burst from the water and crashed into the boat's seating area.
"As soon as you saw it coming there was no time to move and the worst part was you're in a small boat," Will Bryan, who was on the boat with his girlfriend Erin, told the BBC.
Prof Wilson, however, would not have been in the least astonished.
The professor of volcanology knows from four decades of studying supervolcanoes that, big or small, they can be temperamental, erratic beasts.
"Volcanoes are like humans," Prof Wilson says.
"Winston Peters would make a splendid volcano. You just don't necessarily know what he's going to do on a day-to-day basis, or how he's going to react to something. Sometimes you get a massive directed blast and sometimes you get all sweetness and light. Would you predict Winston Peters? No."
Not surprised. And probably not even on the boat.
"There are two schools of vulcanology; the gung-ho types and the cunning cowards," he explains.
"The gung-ho types study active volcanoes. The thing is, when you are looking at a volcanic eruption, my experience is it's quite hard to make quantitative observations of any value. And if you misjudge it, as many people have over the years, you're dead.
"It's a valuable style of working. But what I've done ... I'm in the second school."
He is not quite there, yet.
If anyone knows anything about volcanoes, and more specifically supervolcanoes, it is Prof Wilson.
In the past 40 years he has worked on six of the 10 largest volcanic eruptions the earth has experienced during the past 2.8million years.
That includes the super volcano that created Lake Taupo 25,000 years ago and the sprawling, two-million-year-old "supervolcano of supervolcanoes", Yellowstone, in the United States.
Although it is not a super volcano, Prof Wilson has also taken an ongoing interest in Kilauea, which, since May, has destroyed 700 homes. In 1984, he visited it with US Geological Survey staff and took a spectacular photograph of a television news helicopter dwarfed and silhouetted against the volcano's 450m high, molten magma eruption.
"It's been spitting out several cubic metres per second of molten rock for 35 years," he says.
"It just happens to have shifted where it is pushing that out to where people have rather foolishly put settlements."
As professor of volcanology at Victoria University, of Wellington, he and his students continue to hunt for bits of the puzzle that will afford a big picture of the processes, time scales and factors determining how and when volcanoes erupt.
One project is approaching the problem from a unique angle.
Maori living in New Zealand before Europeans arrived would have witnessed the eruptions of Tarawera, Rangitoto, Taranaki, Tongariro, Ngauruhoe, Ruapehu and Whakaari (White Island).
A researcher is gathering stories and waiata of the people from Lake Rotomahana, southeast of Rotorua. Rotomahana was significantly impacted when Tarawera, which had erupted in about 1315, blew again in 1886.
"This is what we are trying to do with the Maori stories and songs that are available; use their information to understand whether there were signs and symptoms of things happening prior to the eruption.
"So, finding out, for example, how much warning the 1886 Tarawera eruption gave. Would we have picked it up today? Would we have been able to give adequate warning?"
When it comes to plate tectonics, earthquakes have had the lion's share of the attention, Prof Wilson says.
"There are fewer people working on volcanoes compared with earthquakes, so there is a lack of knowledge.
"But what intrigues me, and what I would like to probe at, is that there is a limit to what we can know because natural systems don't follow fixed patterns; they are chaotic."
Earthquakes have a narrower set of variables, most of which relate to the build up and release of stresses as the plates that make up the earth's crust, floating on the caramel-like, rock mantle, push up against each other.
When the mantle pushes through the crust, volcanoes erupt.
"Volcanoes represent molten rock that is created by the water and gases that are coming off the down-going slab [of a plate] reacting with the hot mantle beneath, which partially melts and comes up to the surface."
All sorts of variables, some of them still unknown, determine how the volcano will behave.
There are two broad groupings for volcanoes, Prof Wilson says.
There are well behaved, respectable volcanoes that erupt at regular intervals or have a consistent supply of molten rock.
"They just plug away. Kilauea is one of those. It's only the fact that it's erupting in a slightly different part, that is causing the problem.
"They're very spectacular volcanoes but they follow a nice quiet pattern."
Then, there are volcanoes, like Fuego, in Guatemala, which suddenly erupted last month, quickly becoming the country's deadliest eruption in 90 years.
"Fuego was monitored. Fuego erupts quite frequently. But it produced something unexpected and about 100 people were killed."
These other volcanoes, like Taupo, have "a wild variation" in behaviour.
"Nothing happens for thousands of years, then there's a little piddly-squat eruption or quite a massive eruption that might come just a few hundred years after another one."
A volcanic fire was lit in Prof Wilson's soul on January 23, 1973. He was 16.
"A volcano erupted on an island just off the coast of Iceland called Heimaey. It was a spectacular eruption because it opened right up along the edge of the town. There were all these spectacular images, and they are still circulating. There's one of a church being enveloped in lava and you can see people silhouetted against the fire fountain."
Not long after, at an interview for his application to study geology at Imperial College, London, the young Wilson "waxed on lyrical" about the Iceland volcano.
"It pushed over lousy school marks to get me in. And it introduced me to a remarkable person called George Walker," he says.
Prof Walker, who became Prof Wilson's mentor and PhD supervisor, was an exceptional volcanologist.
Prof Wilson followed Walker to New Zealand, first on a year-long exchange that included two months in the United States (US), at Long Valley, in California, and Yellowstone, in Wyoming. He later returned to New Zealand for more study and then, in 1993, to live and work here permanently.
An abiding interest has been the Taupo volcano, especially the 232AD eruption, the largest after the eruption that first formed the lake.
He has also maintained active research links in the US.
At Yellowstone - where, this week, a section of national park was closed to the public when a 33m fissure opened up - Prof Wilson chose to focus on the oldest of three supervolcano eruptions.
"I worked on the older one because I felt it was being ignored.
"It was abundantly clear to me there were good things to be gotten out of the rock. But it's taken me a hell of a long time to get to grips with it."
If volcanology were police work, Prof Wilson says he would not be a first responder.
"When you're working on old eruptions you realise that what happens in the space of a human lifetime is, in most cases, just a tiny fraction of what is possible with volcanoes.
"In some ways it's the difference between working on an active crime scene versus a cold case. The body has just been found after 17 years and you have to sort it out. I'm more of a cold case kind of guy."
Working on the Taupo 232 eruption, for example, his close observation of rock and soil samples rewrote the history books.
"I was looking at sections that had been labelled as one tephra formation. These deposits had been mapped out by people in the '60s and '70s. I looked at it and then I thought `No, there's another break in there, there's another soil in there'. Then by observing, you realise there are many, many more eruptions represented in that sequence than people had previously recognised.
The implications that flow from such work can be profound.
"So there were two eruptions that had been lumped together that when you actually look at it and map it out carefully you realise they are from two separate vents but are only separated by an extremely short time break ... something of the order of 10 to 20 years.
"Just simple field observations tell you, this volcano, if it has an eruption, its reset time, filling the cistern again back to the stage where it is capable of erupting, could be as short as 10 years.
"So, you have one eruption and you think, `OK that's it for thousands of years'. No. The volcano resets inside the order of 10 years and therefore you are back on exactly the same basis as you were before the first eruption. You can't relax and say,`Thank goodness that's over with'."
Getting a deeper understanding of volcanoes is important globally. But it is crucial for countries such as New Zealand, which largely owes its existence to the presence of a volcano-prone plate boundary.
Otago Harbour, is a prime example. About 13 million years ago, the continental plate of the Otago region was being stretched and had begun to crack, Dr Jonathan West says in his environmental history of Otago peninsula, The Face of Nature.
During the next three million years a series of eruptions occurred that formed what became the harbour.
"New Zealand," Prof Wilson says, "has managed to place, in its wisdom, its biggest economic and social centre exactly on top of a rugby ball-shaped volcano.
"In Auckland, where the last eruption was 500 years ago, there will be another volcano. Although, it may not be for several thousand years."
One new piece of the puzzle is a growing understanding of how wide a view is needed to assess whether an eruption is imminent.
"To monitor the central North Island volcanoes, do you also have to look at the whole state of the stresses, the pushing and the shoving, around the North Island, because that actually is one of the key triggers for magma getting to the surface?
"Around the planet people monitor volcanoes. Now, what we are trying to say is ... it might be all there and ready and hot, but if the crustal stresses block it, it will not erupt. So, we need to monitor and think about things on a much more broader scale."
Prof Wilson says there has not been a single moment at which he has been "tempted to leap out of your bath and go running naked down the street yelling eureka".
Over the years, however, patterns have started to emerge that have allowed him, his students and colleagues to identify how eruptions occur, the timeframes at play and the important factors.
"Then, obviously, the next generation will be able to take that and turn it into smart monitoring of volcanoes, new ways of looking at volcanoes that hopefully will give better warning, that can say with reasonable probability what will happen so that people can be evacuated as necessary.
"That would be a legacy that I would want to see."
In the meantime, he keeps working towards that day.
"So, finding out for example, how much warning the Tarawera 1886 eruption gave . . . that's the sort of thing I'm trying to get to grips with.
"At this stage the answer is we don't know yet ... Would it give you long enough to implement suitable civil defence planning?
"And the hope is, yes, that we can save lives, that we can minimise economic damage."
The talk
Professor Colin Wilson, is touring New Zealand delivering his 2018 New Zealand Rutherford Lecture, "The Life and Times of Supervolcanoes". in Invercargill,
Dunedin and Wanaka, on Wednesday, Thursday and Friday respectively. The talks are free, but registering is advised. For more information, visit online at
www.royalsociety.org.nz/events
