Snowslip advice: swim for your life

Two climbers were rescued on Sunday after an avalanche swept them 500m down Mt Taranaki. Photo / Taranaki Rescue Helicopter Trust

In the chaotic swirl of an avalanche, as you are sucked down into the tumbling mass of snow and ice, there's not much you can do.

It is only as it is slowing towards a stop that you can take some crucial steps to save your life.

Because once you have stopped, and you're buried in snow that feels like concrete, time is very much against you.

"It's a horrible statistic, but you've got about eight minutes to be dug out of an avalanche before your chance of survival plummets dramatically," says Andrew Hobman of the Mountain Safety Council.

On Sunday, two climbers faced the nightmarish scenario when they were swept 500m down Mt Taranaki.

One of the men was free from the snow when the avalanche stopped, while the other was buried with only his hand above the snow, and luckily his companion was close enough to dig him out.

The pair, aged 37 and 40, have been treated at Taranaki Base Hospital for mild hypothermia and fractures and were yesterday classed as being in stable conditions.

As winter brings people out into the snow in their droves, Mr Hobman is urging them to "try not to get caught in the first place" by understanding the terrain and conditions that lead to avalanches.

"If you are unfortunate enough to have triggered one, then the thing to do is yell and make noise and make others aware of where you are, so they watch you."

Generally people trigger slab avalanches, "which start as a cohesive slab and as it moves down the hill, it accelerates very rapidly and then breaks up into smaller and smaller pieces", Mr Hobman says.

"You've got a very short time at the beginning of it to try to get off it.

"Once it's actually got you and it's moving, the next thing is to discard all your equipment. Because your equipment will bog you down, will suck you down into the debris."

The next thing is to try to "swim, to try to stay on the surface of the avalanche".

"They tend to move a little bit like a caterpillar track. And they take you along the surface and then you get thrown over the front of it and drawn deep inside it, like being dumped in a wave out at the ocean.

"And at that point, you are in a complete tumble and you don't know which way is up. You are just taken along with it.

"If it gets to that point, and you're inside it, there's really not much you can do until you start to feel it slow down."

As that happens, it is important to try to create some sort of an air pocket around your face using your arms, Mr Hobman says.

"Because as soon as [the avalanche] stops completely, it tends to set up like concrete. You really can't move anything whatsoever."

OUTDOOR SAFETY CODE

* Plan your trip. Know where you're going, the nature of the terrain and when you will be back.
* Tell someone. Discuss and leave your intentions with someone you trust.
* Be aware of the weather and avalanche conditions. Check avalanche advisories at www.avalanche.net.nz.
* Know your limits. Learn to manage yourself in dangerous avalanche terrain. Take a course.
* Take enough supplies. Always carry a transceiver, shovel and probe.