Life under Ruapehu as risk of eruption increases

Friday, 13 May 2022

Mt Ruapehu’s crater lake temperature has risen, prompting locals to reflect on the mountain's previous eruptions. Video first published May 13 2022.

Weston Kirton knows exactly where he was at 7am on June 17, 1996. He was at Whakapapa Village on Mt Ruapehu. It was his birthday and he was dropping his daughter off for a training session ahead of the ski season. They had driven through fog, and risen above it into a beautiful day. So he has those aids to memory.

But he also has the extraordinary experience of watching the mountain blow.

He saw a plume of black ash rising into the air. He saw a clear blue sky filled with thunder and lightning.

* Huffing and puffing - Ruapehu lets off steam as crater lake temperature rises

Weston Kirton was on the spot as mayor when Ruapehu blew in June 1996.

* What happens if Mount Ruapehu goes bang?

Whakapapa is a study in light and shade.

Gone fishing: Department of Conservation scientist Michel Dedual.

Then his phone started ringing. Kirton was Ruapehu mayor at the time and a BBC reporter who happened to be up there was one of the first to score an interview with him. Kirton spent an hour or so on the mountain before heading home to Mananui just south of Taumarunui, driving through hastily set-up road blocks. No sooner was he home than the phone went again, this time to pick up his daughter; the training session, which incredibly had carried on, was finally being abandoned.

The tremors continued, the volcano kept erupting and that night, from home, Kirton and his family could see the red glow on the mountain top the best part of 50km away.

Michel Dedual gets ready for a spot of fishing in the Tongariro River.

In the aftermath, with ash falling up to 300km from the mountain, airports including Rotorua were closed, Civil Defence kicked in, Kirton as mayor got involved in a campaign to support skiing related businesses, and the council froze its rates. Word also spread that the highway near Kirton’s place provided a good vantage point, and for weeks motorists were pulling over, parking up and causing chaos, he says.

There was a further eruption the following month, another in 2007, and now the crater lake is heating again, fluctuating as high as 41C.

The weather clears on Tuesday enough for the mountain to become visible.

Is Kirton, these days a regional councillor, sweating on a further eruption? “No-one is, really. We don’t see it as a huge risk.”

By the time Kirton had his up-close experience, Ruapehu had been rumbling and erupting off and on since 1995, including an eruption in October of that year. A strange thing happened the day before that one. By chance, about 100 trout had been tagged with radio transmitters at the time, to find out the impact of power company Genesis’s river flow management. The trout started heading downstream towards Lake Taupō. Or the adults did; the juveniles stayed put. That was their mistake. The next day Ruapehu blew, the rivers became toxic from a lahar and many of the fish died. Taupō was a big enough body of water that the trout there survived. The adults had presumably felt tremors in the water and swum away from the source to safety. They were, in effect, early detectors of the coming eruption.

Department of Conservation Taupō fishery scientist Michel Dedual, who retires next week, recalls the eruption clearly. “It was a brilliant day, a glorious blue day, magnificent, and nice and warm. But you could see in the sky an absolute black plume. And early in the morning, the sun was still low in the sky. So it was perfectly normal, except for that really dark plume. But then as the sun rose further up, it became almost in the shade. And it became freezing. It was very, very weird, like almost sort of a nuclear dawn.”

An icon of the mountain finally shows itself on Tuesday.

It was also fabulous, and in the following days he drove his kids along Desert Road to soak up the sight.

And then another strange thing happened. The ash deposited on the lake slowly sank through the water, carrying algae with it. The water, washed clean, became crystal clear. And the first floating algae to recolonise was a species that perfectly suited trouts’ feeding habits. The mass die-off also meant less competition for food. By 1998, the lake had trout at sizes that hadn’t been seen since 1920. It was a great time to be fishing around Taupō. An eruption is not necessarily, Dedual remarks, all doom and gloom.

As it happens, modern technology and ancestral knowledge meet when it comes to fish acting as an early warning system. Traditional volcanology expert Che Wilson, of Ngāti Rangi, which is based on the southern side of Ruapehu, has a strikingly similar story to Dedual’s.

Some families of the Karioi area, where his father is from, get a stunning view of any lahars launched down the Whangaehu River by eruptions. They have seen eels, sensing an impending lahar, either swimming up tributaries of the river to get away from danger or wriggling across land to make their escape. As with the trout, there are, he says, always a few that get caught.

From left, friends Ruth Gerzon, Maro Arcus, Moetatua Turoa and Christa Hunziker rug up for a photo.

Wilson has been heeding the crater lake’s current warming. “I'm keeping an eye on the mountain whether GNS is telling us things are happening or not. You know, he's our ancestor. So we see him differently, we don't see him as a hazard or risk. We deliberately choose to live at his feet. And when you live at the feet of an active volcano, you have to continually observe the changes.”

He knew before the first reports of the lake venting that something was afoot because he had seen a phenomenon called tahuarangi, which means the burning red skies. Then his wife phoned him to say his mountain was steaming. Okay, that makes sense, he said.

There are also indicators that tell him and his iwi whether they should be worried, places on the mountain where they check the likes of sulphur deposits. Wilson, who lives in Hamilton, has had people go and have a look. “So far, so good,” he says, speaking on Monday.

“Nine times out of 10 those observations are bang on and occasionally they’re not, but it’s no different to volcanology. Volcanology is about 60 to 70% on the mark and the rest is guesswork.”

It all comes from hundreds of years of observation, with the knowledge recorded and passed on through song. Wilson says Ngāti Rangi are happy to work with volcanologists to help piece together the puzzle. “It's really important that we maintain the traditional practices of recording, like through song, as well as utilising the modern tools so that we can get the best read possible.

“It was different in the past because we were looked down at – even though science is the study of observation.”

That accumulated knowledge means, for instance, marae are situated where they will be safe from lahars. Locals reckon it’s time to leave when the marae decides to leave, he says.

He says his iwi, along with scientists, successfully opposed a proposal by some Ruapehu councillors in the wake of the 96 eruption to bulldoze part of the lake’s rim to prevent it filling up again. “It was ridiculous. Not only is it a sacred place and a burial ground for us, but more importantly, why try and beat nature?”

Between the warning system now in place and traditional methods of observation, he thinks “we're in a pretty good place to be sensible and safe”.

And he adds: “It's always a stunning view to see anything happen from the mountain.”

Plateau Lodge owner Andrea Messenger: The message is, it’s all safe.

The Ruapehu connection

On Monday afternoon, a group of three friends from around the Whakatane and Te Whānau-ā-Apanui area are sipping wine in The Chateau’s large lounge, while others are gradually arriving to join them.

Moetatua Turoa and his partner Christa Hunziker try to get down here at least once a year; Turoa, as the name suggests, connects to the area and he knows Che Wilson.

“We come down the Whanganui River to reconnect ourselves with this side of my whakapapa,” he says.

National Park Four Square owner Dhruv Dewan is relaxed about the heating crater lake.

Turoa has seen Ruapehu blow in the past when he was in Waiouru in the 1970s. Hunziker, meanwhile, who is Swiss, says Ruapehu reminded her of home at first sight. Then she came across a poster warning what to do in case of an eruption. “We don’t do volcanic eruptions in Switzerland.”

Ruth Gerzon, who has organised this get-together which is set to swell to 18 people, joins Turoa, Hunziker and Turoa’s cousin Maro Arcus in the lounge. Gerzon is the most recent to have climbed to the crater lake, about six years ago, and recalls the lake being darker and less blue than she expected. With a 2km exclusion zone in place, she is disappointed that she won’t be able to do it this time. “It’s a wonderful trip.”

There has been a cluster of earthquakes in Whakatane earlier in the morning and talk turns to Whakaari, with the terrible toll taken by its 2019 eruption bringing to mind by Ruapehu’s alert level two activity.

Taumarunui farmer Luke Pepper will be racing for a vantage point should the mountain erupt.

“I think Whakaari is a release valve, eh,” says Turoa.

If Ruapehu is active, it’s releasing out through Whakaari, says Arcus.

Ready to pedal the Old Coach Road bike trail are, from left, George Spiers, Jilly Lambert, Helen and Simon Wenley.

“It's called Whakaari because it appears like a play, and disappears,” Turoa says. “Some days you can look out there and you don't see it. It's a show. That's what Whakaari means, it's a show.”

Whakaari, unlike Ruapehu, is female, Arcus says. “She's a female, she flirts her skirts.”

Today, however, at the source of all the pressure, little or nothing can be seen; the weather has closed in like melancholy and the very few people out and about are workers rather than visitors.

‘A living breathing thing’

Because of the weather, shuttles to take hikers to the Tongariro Crossing are being cancelled. In nearby National Park, Plateau Lodge owner Andrea Messenger says crossings were also being cancelled when the media first started reporting the rising crater lake temperatures, but that time it was hikers taking fright.

“About a month ago when it first hit the media, everyone was calling up to cancel their booking. And that was extremely tough because we're just coming to the tail end of Covid. So here we are, we've finally got full bookings and they were all cancelling.”

But Ruapehu and Tongariro are not connected, she says, and there was no danger. “I honestly believe that's the message that really needs to go out is, it's okay.”

These are baby volcanoes, she says, and the prevailing wind tends to carry ash away from the town. Even if Ruapehu “decided to burp”, National Park would be unaffected. “It might close the ski field for a couple of days, and that's about it.”

TCB Ski, Board and Bike owner Ben Wiggins says the mountain needs to be treated with respect.

A block or two away, Four Square owner Dhruv Dewan is similarly relaxed. The Central Plateau has been cooking for a long time and the mountain will do what it will do.

Is anybody talking about the crater lake? “No.”

Except the media, obviously. “You guys need something to write about. It's doing something that you can write about, something unusual and different from what its normal behaviour is. But for us living here, well, I consider it to be a living breathing thing. It's alive. It's an active volcano. So it's going to do stuff. It's going to not always behave the same way. And you have to just go with it.”

Dewan, a canny business operator as well as a philosopher, seizes the opportunity to show off his store, which admittedly is impressively stocked with a wide range of goods. “I'm all about consistency,” he says. “It doesn't matter what time of year it is, I still maintain a certain level of stock.”

A dark and stormy day. Doc senior ranger Toby O’Hara on Ruapehu.

Taumarunui beef, sheep and dairy farmer Luke Pepper, who is Federated Farmers Ruapehu president, has stock of a different kind to attend to, and the warming crater lake is low on any list of things to be concerned about. It’s not the talk of the town, he says, though it is in people’s minds, particularly tourism operators.

Pepper was a new farmer in Tirau in the mid 1990s, when he woke up one morning to see grey Ruapehu ash all over the place, covering cars and machinery. A concern this time, should the mountain go up, is the lack of rainfall to wash any ash off the grass. He recalls up to a couple of thousand sheep died after eating ash-covered grass in the 1990s eruptions.

Then again, if Ruapehu does blow, Pepper may not be thinking about stock right off the bat; he plans to race to the nearest vantage point to watch the spectacle.

Rings around the mountain. The lahar paths are shown along with exclusion zones on this DOC map.

Volatile history, bustling town

The next morning it’s still grey, a wind is swirling, but Ohakune, by contrast to Whakapapa on the other side of the mountain, is pumping. Crossing the road requires patience and timing, and most of the car parks are full. May is off season, so these must be mostly locals filling the shops and cafes.

Four cyclists entering the Mountain Rocks cafe for breakfast, however, are out of towners.

They’re here for the Old Coach Road bike trail. It’s the third time for Jilly Lambert and George Spiers, and they’ve brought their friends Helen and Simon Wenley to introduce them to the ride. They’re getting a shuttle to the far end and will take their time coming back on their e-bikes, stopping to check out the history markers along the way.

The quartet stopped at Tangiwai on their way here, another marker of this region’s volatile history. Just back along SH49, a memorial marks the spot where on Christmas Eve 1953 a rail bridge over the Whangaehu River collapsed under the combined pressure of a massive lahar from Ruapehu and the weight of a train, killing 151.

As for the current threat, Lambert has the solution. “When it starts to rumble and you hear a noise, I think you'd be best to get on your bike and turn the motor on and pedal like mad.”

Spiers says they’ve been keeping an eye on Geonet, which says it’s safe at level two. “But you can't help but remember that's what they said about Whakaari/White Island.” He was on Whakaari about a year before its eruption. “You've got steam coming up and you've got rumbling going on. You've got little earthquakes going on. So you've got exactly that up here. Whakaari was level two, that [Ruapehu] is level two, the two are connected, I think.”

Then he strikes a lighter note. “If it goes up while we're up there, we will be biking back pretty fast.”

A block further up Goldfinch St, Ben Wiggins, owner of the TCB Ski, Board and Bike shop, has seen it all before, including the media interest; he reckons it’s almost an annual thing. The born and bred Ohakune local says his bigger concern would be if there was no activity; that would be ominously out of the ordinary.

Both he and retail store manager James Foubister have emergency kits and generators at home, but that’s nothing to do with eruptions. Foubister says during the mid-1990s eruptions, Ohakune got ash only once, and heavy snowfall bringing down power lines is the more likely trigger for a spell holed up at home.

Wiggins, who has skied and hiked around the mountain and the crater lake, says it’s about showing respect. “Mt Ruapehu, it's a very spiritual place, so culturally, you need to respect it.” There is also the impact volcanic activity can have. “And then obviously, the last thing to be respectful of is that it's a large volcano sticking out of the Central Plateau and wind and weather and stuff can change rapidly.”

Wiggins, like Dedual, has a vivid memory of a 1995 Ruapehu eruption. He had just finished a day’s skiing and was returning to his car, when he heard a collective “ooh” go up around him. He had his back to the mountain and at first thought there had been a car accident. Then he turned to see the ash plume and car-sized boulders getting tossed from the crater.

They stood and watched in amazement, and noticed a group of about five climbers who had been heading towards the crater. “Watching those guys split, and then come down at high speed was quite entertaining to watch.”

The excitement today, however, is around the massive increase in summer visitors, much of it thanks to the development and promotion of the Old Coach Road track. Ohakune used to be a party town with a ski problem, Wiggins jokes; now summer is proving just as fruitful. Like Dewan, he seizes his opportunity. “The one thing we've got an abundance of is stuff to do outdoors, because we've got the mountain behind us, we've got multiple streams going off in different directions. So if you like the outdoors, you like trails, you like tracks, you like biking, you like hiking, there's just a whole heap to do.”

A stunning place

Further up the road, on the outskirts of Ohakune, DOC occupies two unassuming buildings behind the Ngāti Rangi office. Senior ranger Toby O’Hara says the main mechanism the organisation, as land manager, is using to keep people safe at level two is the 2km exclusion zone.

Enforcement is virtually impossible, but the number of people who might stray in there is tiny; there are no tracks or huts in the zone, though it does clip the top of the Turoa ski area. O’Hara pulls out a map that shows the exclusion zones, and lahar paths marked in red and pink, including a path into the Whakapapa ski field. Should something happen, that’s when what O’Hara describes as a world-leading eruption alarm system kicks in – a vast improvement on what was in place during the 1990s.

Startled skiers on Whakapapa will hear a siren followed by a voice instructing them to get to high ground. It will be alarming and memorable. Unnoticed by skiers, text messages will also be sent, along with radio tones to ski field staff, and calls will be made within a set time to key people.

O’Hara, who is also involved in search and rescue, has been living in the area for 15 years.

“It's so accessible. You can go to a bunch of different places and see awesome, amazing things. You’ve got the alpine environment, which you don't really have anywhere else in the North Island. And then you add into that, I guess, the volcanic aspect, and it just makes it a really interesting place to work.”

On Tuesday afternoon, the weather is finally starting to lift, and the photographer has a chance of a shot showing the mountain. We head back up to The Chateau. This time, there are plenty of people around, walking, sightseeing, loafing. We carry on further up and pull over into a large, almost empty car park.

The light is shifting, casting glints and shadows everywhere. Christel starts clicking, and finally knows she’s got the shot she wants. The summit is somewhere ahead of us, and behind us is the vast plateau, dappled in sunlight and shadow. This place is good for the spirit. Right at our feet, in a jarring note, are burnout marks on the asphalt. The mountain calls everyone.

Dewan, who was born in India and did some globe-trotting before fetching up in New Zealand and then buying the Four Square business 15 years ago, has chosen to park himself right beside this active volcano when he could have gone anywhere.

“Why wouldn't you? Have you seen the place on a sunny day? It's amazing. I mean, every day you open the store you're like ‘holy moly, look at that. Wow. Just amazing. What a stunning place.’”