Avalanche on Mt Ruapehu shuts upper slopes of Tūroa and Whakapapa

Monday, 6 August 2018

Two men had a narrow escape from an avalanche 'big enough to destroy a small town', but the cascading slip carried away a large snow plough, damaged a ski-lift tower and shut down Mt Ruapehu's upper skifields.

It is not the first time the ski-lift tower has been damaged either, with severe ice causing a similar situation before.

Two Ruapehu Alpine Lifts staff were setting up for the day on Monday morning before the Tūroa field opened, at a ski-lift building on one of the upper slopes, says a regular skier, who heard about the incident from staff, but asked not to be named. 

The pair, aged in their 20s, were outside watching as the avalanche control team set off preventative detonations on the upper slopes. One of the men had just parked a 'snow cat' grooming machine, which looks similar to a big bulldozer, the regular skier said. 

'They were all on radio, so they all knew [the blasting] was going on, but they weren't expecting it to go as big as it went.

**READ MORE: 

* Passengers say brakes failed on bus that rolled, killing child

* Bus in fatal skifield crash had a history of failed inspections

* Mother of 11-year-old girl killed in bus crash at Tongariro National Park

* Hit the mountain with cheap skis and snowboards**

'They got radio calls and ran into the safe zone in the [ski-lift return] building. The avalanche came down and took the cat.' 

The avalanche had left a 700-metre debris field and carried the cat about 200m down a ski run called Vertigo, probably writing it off, he said. 

The building staff took shelter in a 'big reinforced building designed to take a lahar going over it, but the door got mostly buried'. 

The slope the avalanche came from 'doesn't usually avalanche. It's a rarity', the skier said. 

'They're a little bit shaken and quite a lot of them are extremely excited they got to see a very rare occurrence. But because of all the protocols in place they are not that stressed about it.'  

Ruapehu Alpine Lifts chief executive Ross Copland said avalanche control explosives were being set off by a snow safety team on a different slope when an 'adjacent' snow face collapsed in a large avalanche that was not expected. 

He confirmed a tower from the High Noon ski lift, and a snow-grooming machine were damaged, and the avalanche had come 'in the proximity' of staff setting up for the day, but said all staff were safe and accounted for and investigations would have to be carried out before he commented further.

'They've done an amazing job. We've had a really great snow this year. It does increase the avalanche risk.'

In a video update on Monday evening, Copland said the shape of a building uphill from the ski-tower 'launched' the snow into the top of the tower.

A similar thing happened a couple of years ago when there was severe ice on the skifield, he said.

The force of the snow has bent the tower, putting the lift out of action. The tower would need to be taken down and disassembled to fully assess damage.

If the haul rope was damaged, it could take some time to source a replacement, he said.

'Basically, it's just one step at a time.'

The avalanche meant the risk of another one happening was 'well and truly clear', he said.

'The pros and cons of having a massive snow season is that you do have these avalanche conditions.'

'BIGGER THAN EXPECTED'

The avalanche started above the top High Noon chairlift about 8.30am before the Tūroa skifield opened, and the upper slopes of both the Tūroa and Whakapapa sides of the mountain have been closed for Monday.

'It was about size four, which means it is enough to destroy a train or a small town. It's about 10,000 tonnes in snow,' said Loik Lassueur​, the Mountain Safety Council's alpine adviser. 

'[It] was bigger than expected. In terms of New Zealand scale, that's very big. We rarely get stuff that big.' 

Staff arriving at the lower areas of the mountain in the morning could see the avalanche clearly, said a Tūroa staff member named Samantha, who did not give her last name.

Ski patrols had headed out to do avalanche safety checks of the whole mountain and check the area the avalanche covered, and engineers are investigating the extent of problems at the High Noon chairlift. 

Staff set explosives off remotely at skifields outside skiing hours if there is potential for avalanches, Mountain Safety Council chief executive Mike Daisley​ said.

'This is part of normal operations and is a very good thing for the safety of skiers. 

'It ranges from helicopter bombing and tripping the explosives with remote detonation, and they have air-powered cannons to fire the explosives that are on a remote. The snow safety staff can place them and hightail it down and remotely detonate.' 

The damage to the chairlifts in this avalanche was 'not ideal', he said, 'but the snow does what it wants after it's triggered'. 

This was the third large avalanche on the mountain in recent days.

Observations from helicopters and binocular searches from high up the mountain had also spotted two other avalanches that occurred naturally in recent days in back-country areas off the skifields, Daisley said.

One was size 3.5 – almost as big as the most recent avalanche. 

Conditions on the mountain right now were dangerous outside of areas that had been checked and cleared for safety, Daisley said. He asked people not to go outside the ski boundaries. 

'We'd have serious concern for anyone heading into the back country.'

A New Zealand Avalanche advisory forecast for Ruapehu has been changed from 'considerable', to 'high – don't go'. 

However, the beginners' Alpine Meadows section was safe and open, a Tūroa staff member said. By 10am on Monday many skiers were already out on that section.

Updates will be posted on mtruapehu.com/turoa and the Mt Ruapehu Tūroa Facebook page.