Avalanches Fierce Earth

Skiing, snowboarding, sledging!

Here in the Alps, it's full of people having the time of their lives

in some of the most spectacular scenery on the planet.

But snow, the white fluffy stuff that everyone comes here for,

the very thing that makes it fun,

can also put you in mortal danger.

Here in the mountains, it's the word everybody fears...

-Avalanche!

-Avalanche!

Get suited and booted, cos we're travelling to avalanche country,

skiing in the shadow of the biggest threat in the mountains...

This is the run where the avalanche happened.

..checking out cutting-edge survival tech,

taking on nature in a man versus snow race...

..and prevention - fighting avalanche with avalanche.

What happens when the ground shakes, the seas rise up

and the air tears itself apart?

The Fierce Earth team move in,

taking on the most powerful forces on the planet.

Get ready for Fierce Earth -

the Earth, and how to survive it.

This is an avalanche.

Hundreds of tonnes of snow travelling in excess of 150 miles per hour.

Spectacular, beautiful, deadly.

If it hits you, you're along for the ride all the way to the bottom.

And the cause of this terrifying moving cliff of snow?

Well, sometimes it's this.

Me.

Well, not just you, Dougal.

In 90% of all avalanche incidents where people get hurt,

it's the very people caught up in the avalanche

or their ski party that trigger it.

Check out Dougal's skis.

Every time he makes a turn,

he moves the snow and that creates lots of mini avalanches.

Take a close look at that,

because it holds the secret to avalanche survival.

You said you wanted a closer look!

To understand avalanches, you've got to understand snow.

We've come to Tignes,

a major ski resort over 2,000 metres high in the French Alps.

Tignes has over 300km of marked ski runs called pistes,

and many more miles of unmarked off-piste skiing.

In short, there's a lot of snow.

Snow is always cold and always white,

but, other that that, it has endless variety,

which can all add up to increased avalanche risk.

How snow falls...

Does it float gently down like a Christmas card?

Or get blasted out of the sky like a blizzard?

How it collects...

As snow lands on the ground,

it can build up in soft drifts or pack into icy sheets.

The weather...

Snow can melt or refreeze days or even weeks after it fell.

It's constantly changing.

We all know that every single snowflake is unique, right?

As individual as you and I.

But that hasn't been conclusively proven, Dougal.

The classic snowflake, the six-pointed crystal,

interlocks more easily with other six-sided snow crystals

to form a stable layer.

But some snow crystals have less points, almost like grains of sugar.

They can't interlock and are therefore unstable.

And then, with all the freezing and unfreezing,

there's lots of shapes in between.

Some are unstable, and some are very stable indeed.

How snow falls, how it collects, the weather,

the snow crystals themselves...

It's clear that predicting an avalanche is far from easy,

and prediction is pretty urgent here in Europe's Alps,

with around 250,000 avalanches every year.

In 1999, high levels of snow and changing weather created

an unstable layer of snow high above

the village of Galtur, in Austria.

Over 150,000 tonnes of snow

travelled down the mountain

in less than a minute.

31 people lost their lives.

Scientists can't predict avalanches,

but by studying the snow pack that has collected on the mountain,

they can tell when and where avalanches are more likely.

As can be shown by making a classic French gateaux.

Avalanches are formed when the weight of snow above, the load,

is too heavy for the snow beneath

and the whole snow pack fails.

Avalanches usually form on slopes that are between 25 and 45 degrees.

Too flat, and the snow that's settling

is pushed into the ground by gravity.

Too steep, and the snow doesn't actually settle at all

to form to dangerous levels.

But then, you have to add the ever changing snow types into the mix.

So, we have an unstable layer...

-Cream here.

-And then a more solid stable layer on top of that.

And maybe then some more slippery, slushy stuff on top of that.

So some more creamy snow.

And then, perhaps some graupel -

a type of snow that's like icy ball bearings.

And it's very unstable. And then, another solid layer.

And then, we're building the gateaux with more slippery,

slushy stuff, and then we've got some more stable snow.

-Oh!

-Oh!

And then, the snow is all melting and reforming,

melting and reforming, creating some stable and some unstable layers.

And there you have it, a teetering gateaux, ready to fall.

And it's now that the conditions are ripe for one of the most

feared avalanches of all -

the dreaded slab avalanche.

The weak layers can't support the strong layers

and the whole slab slips away.

The slab avalanche is one of the most dangerous

and causes the majority of skiing fatalities.

In 2012, there were 70 avalanche casualties in the European Alps.

Despite the risks, winter sports enthusiasts

from all over the world travel to the Alps to have fun on the snow.

And there are many that call the mountains home.

This is Charles and Mathieu Navillod in action -

two local brothers who grew up in Tignes.

They're expert skiers,

who have represented France in international competition.

But they also know about avalanche danger first hand.

Charles is lucky to be alive.

I met up with him and his brother to find out his avalanche story.

So, as brothers, you've been growing up here in the mountains.

Tell me a little about that.

Yeah, we start ski at two years old.

-Wow, so you're literally born with skis, almost.

-Yeah.

What do you like so much about off-piste skiing?

-It's freedom.

-Feel free, like flying on the snow.

Be alone, far from the city.

You must, obviously, develop an understanding

and a feeling about avalanches.

We learn every day in the mountains and we never have zero risk.

Like, today, it looks not dangerous

but we can find some steep parts, we can make avalanche, for sure.

-So we have to be careful every time.

-Always have to be aware.

I mean, it's really hard to stay at home when it's, like,

beautiful powder snow, but sometimes we have to say,

"OK, today, it's too much risks."

It's clear that Charles and Mathieu are experts skiers,

but even they have a near-miss avalanche tale to tell.

They want to share it, so that others might learn from it.

What happened to them

could happen to anyone who leaves the smooth, marked piste.

Guys, we've just, literally, stepped off a very easy piste

and, clearly, just over here it's very steep and definitely off-piste.

What is it we're going to go and see?

Two weeks ago, we had an avalanche just there.

An avalanche just over here?

Yeah, just next to the slope, so I'm going to show you.

-So, you can take us to the place where it is?

-Yeah.

Brilliant! Let's go and have a look.

You should never go off-piste

without an experienced guide.

I'm able to because Charles

and Mathieu are professional ski instructors.

Off-piste is where the snow is deep and unpredictable and the risk of

avalanche is greatest.

Two weeks before our meeting,

Charles was skiing through

the trees here when he was caught up

in every skier's worst nightmare.

This is the run where the avalanche happened.

So I started by the trees there.

The whole avalanche was recorded

on Charles' mini helmet camera.

Here you can see how the snow

sweeps him off his feet

and over the edge of the cliff.

I did the first turn

and avalanche started directly.

So, I have to drop that cliff down here,

but the avalanche goes so fast.

You feel really the power of the snow for four, five seconds.

It was really short, but it feels so long and it was scary

and I could only think about protecting my face.

So what actually stopped you going all the way down the

-hill with the avalanche?

-So, that small tree.

Wow, it doesn't look like much

but that's the actual tree that saved your life.

And how much further did the avalanche carry on?

It stopped, like, 20,

30 metres down the snow.

It was a really short avalanche, like, 80 metres from the top.

Did you badly injure yourself, at all?

Well, I hurt my face, a lot of blood on my face.

Hurt my leg, but it was two weeks ago and I'm here,

so I guess I was really, really lucky.

How do you feel now about skiing this area?

I feel good, I respect the mountain.

You know, sometimes it's like that, mountain is stronger than you.

Charles is one of the lucky ones.

He was caught up in an avalanche and lived to tell the tale.

But there are ways to increase your chances of survival,

if the worst does happen.

This is footage of a professional snowboarder

caught in a real-life avalanche.

He's saved by the latest kit that has been deployed,

nearly 400 times and claims

up to 95% survival rate.

So, what's the secret?

This.

HE LAUGHS

Wow!

Like all of the best ideas,

the avalanche air bag is incredibly simple.

It works on the principle of granular convection.

Granular convection simply means that large objects tend to move

to the surface when they're shaken

around with lots of small objects.

Time for another French treat!

The bonbon.

And there's only one thing better than a bonbon - lots of bonbons.

The only problem now is, I can't get

at my big, red bonbon because of all of these little, white bonbons.

However, if I use granular convection and shake the bottle...

Voila! I can get at my red bonbon.

And that's exactly what the avalanche airbag does.

When I inflate it in an avalanche,

I suddenly become a giant human-size

bonbon and I float up amongst all of the snow particles to the very top.

C'est magnifique! Woo-hoo-hoo!

Later in the show, I'll be going off-piste with a ski rescue patrol

and witnessing an avalanche for real.

But first, Clare's hitching a ride on the machine that helps

skiers stay on the beaten track.

It's just gone six o'clock here, in Tignes,

and the last of the skiers have gone back to the ski resort for the night.

It's peaceful again up here on the mountain...but not for long.

That is a state-of-the-art piste basher, it weighs nine tons

and does a maximum speed of 22 kilometres an hour but the best

thing about it, it goes up and down really steep mountain sides.

And I'm going to hitch a ride.

Ha-ha!

The piste basher is human beings' attempt to turn

unpredictable snow into smooth, skiable piste.

SHE SHRIEKS

Bladed caterpillar tracks

allow bashers to travel pretty much anywhere on a mountain.

So they're sometimes used in avalanche incidents to ferry

rescue teams and the injured.

Hundreds of skiers and snowboarders leave bumps

and ice all over the piste.

Basher drivers like Didier have to work through the night.

I you're going to be travelling on the mountain side,

-this is the best machine to do it.

-Yes, definitely.

The snow just falls either side, it's a perfect

machine for a mountain side.

So there's no steering wheel, so how do you control this machine?

I control it like a tank. One for the left, one for the right.

This machine's got so much control, as well as power.

I'm having to brace my feet right now cos we're really going downhill.

So what is your job after an avalanche?

We can intervene, erm, after the avalanche

to rescue some people with the pisteurs.

We're on top of the world here, it's amazing!

There's something about being on a mountain side

when everyone else has gone home.

So when all the skiers

and snowboarders are asleep in their beds,

anticipating the next day's snow, these guys are out all night,

keeping the slopes safe so they can have a good ski tomorrow.

They do an amazing job!

Smooth pistes are just the beginning of keeping skiers safe.

The real avalanche safety work is going on all over the mountain,

night and day.

I've hooked up with the Tignes ski patrol,

whose job it is to keep the slopes safe.

The team numbers over 50 crack skiers, called pisteurs,

plus several rescue dogs.

First job of the day is to set the avalanche warning level.

The lifts have only just opened and the slope's already packed.

We have to tell people the avalanche risk.

Today it's an avalanche risk of two.

On a scale of one to five, two's moderate.

So, Sebastian, there's not really much risk at all?

Today, the risk is moderate, but still a risk.

Last week, again, some people was buried and it was a risk two.

Wow, OK.

So people can still get caught in avalanches even

when the risks are relatively low.

We have coloured flags, so this flag here is a black and yellow flag.

That's for level three and four, we don't need that.

I'll give you that back.

What we need is a level two, yellow flag.

So, we'll hoist this and this is very important,

because at all of the stations they have a flag flying with a colour

that tells people immediately from a distance what the risk is that day.

So they can be prepared and ready to ski as safely as possible.

Yeah, we're flying away! Lovely!

Before venturing off-piste, it's essential that every

skier in your party has the right kit and knows how to use it.

These French teenagers are getting transceiver training.

Each skier's transceiver sends out a signal that the other

transceivers can pick up,

if one of the skiers is buried under the snow.

If an avalanche hits, it's your friends that could save your life.

So, Sebastian, maybe you can explain a little bit about how these work

when they're communicating with each other.

Yeah, exactly, you need two beeps and it's the same frequency

and if I want to find you, I put the transceiver to the search...

Search, yeah.

..erm, like this.

TRANSCEIVER BEEPS

I can find you.

BEEPING GETS LOUDER AND FASTER

Incredible! So you hear the beeps there,

when they're further away from you, the beeps are very slow.

And as the transceiver gets closer to the other transceiver,

it starts to beep much more rapidly.

And so, by going along the snow

and listening to the rate at which the beeps are going, you can

start to home in and search for your buried victim.

You told me that you've buried one of these

transceivers in the snow behind us.

Yup.

So our job now is to go and try

and find what looks like a needle in a haystack.

In avalanche rescue, every second counts!

Your chances of survival drop rapidly after 15 minutes

trapped under the snow.

The clock has already started ticking down.

Right, now, you take off your skis.

So we think it's somewhere close by here, what do I do next?

You must be across, over there.

OK, until you get it more and more.

-Exactly.

-So, I'll do that then.

TRANSCEIVER BEEPS

It's got lower there...right.

Getting faster again.

Zero seven, zero nine.

Essential avalanche survival kit includes a collapsible probe

that can be assembled in seconds.

-OK.

-OK, we think it's just down here.

So using the probe to try and find the location of the victim,

the person.

I've found something there.

And the final stage, we have a collapsible shovel cos it's

the quickest way possible of digging down to try and find the victim.

Every second counts...wow, there's something there.

There's a...

a rucksack...

Woo!

TRANSCEIVER BEEPS QUICKLY

And there you go, it really works, thank you.

Excellent stuff.

Remember, the best thing is not to be caught up

in an avalanche in the first place.

Keep your wits about you when venturing off-piste

and follow our avalanche survival tips.

One, always check the avalanche risk flags

and remember that avalanches can happen whatever the warning level.

Two, never ski alone.

A guide, a personal rescue kit

and a transceiver are minimum requirements.

Three, snow will take the path of least resistance.

Avalanches are fast but lazy.

So you might be able to take ski sideways or even move upwards

out of its way.

But why can't you just outrun an avalanche?

Sounds like a challenge for Leo.

Temperature, a constant -5C.

A vertical drop of 50m.

170m of pristine man-made snow.

This indoor ski slope is about to become my Fierce Earth

avalanche survival laboratory.

I spend a lot of time in the mountains

and avalanches are something that really scare me.

You have to treat them with the utmost respect.

There are a very dangerous thing.

Today, I'm going to see if I can outrun one.

To be honest, I'm not too sure.

My challenge is simple.

Ski as fast as I can down the slope to outrun an avalanche.

As this is a laboratory experiment, the avalanche will be virtual -

computer-generated.

Who will be faster? Me or the snow?

There's nowhere to hide,

but I can give myself the best chance of beating

the avalanche by making sure my skis are in tiptop racing condition.

So when you ski down a slope, you don't

slide down on the bases of the skis,

you cut your way down on the edges.

They're like knives that cut into the slope.

Re-wax the base of the skis.

This wax is to make me go extra fast.

I adjust the bindings to make sure

they release my boots in the event of a fall.

And then, it's time to focus on the challenge ahead.

I'm all set.

But there's one other element to add to the avalanche laboratory.

I need an accurate measurement of exactly how fast I'm skiing.

So I've called in the professionals.

Police officers Paul and James

have brought along their super accurate speed gun.

How did I do?

Not bad. We don't normally approve of speeding though!

-36mph.

-36mph. That's not bad, eh?

Let's have a look at what that would be like

with an avalanche chasing me.

36mph is pretty fast,

but even slow slab avalanches travel at up to 80mph.

Even with a head start, you can see

how quickly the snow catches me up.

Lucky for me, the avalanche is virtual.

Jeepers! I would have been toast.

I'm overtaken almost immediately

and that's on a well-groomed indoor slope,

skiing calmly with no pressure.

So chances of outrunning an avalanche in reality?

I'd say pretty much zero.

There's a lesson here. Don't cause an avalanche in the first place.

Ski hard, ski safe.

Back in Tignes, I'm up early to rejoin the ski patrol.

I catch a special lift with Sebastian to the top

of the ski area.

The slopes have to be empty for the big event we've got planned.

It's a great privilege to be up in the mountains with

nobody around, but there's some serious work to be done.

These automated gas explosion blasters stop snow building up

to dangerous levels.

I've just stopped on the piste here, just above us

you see these strange pipes sticking out of the mountain. That's Gasex.

On the way to meet the patrol, it's clear the daily battle

against the avalanche is already well under way.

And we're just about to hear one of them go off now.

LOUD BLAST

Wow!

You feel the power there,

that's what's needed to set the avalanche off.

And we're literally a few tens of metres from the piste.

It shows you how close you can be to avalanche danger even on the slopes.

Incredible.

LOUD BLAST

Wow!

But the automatic snow blasters are small fry compared with

what we've got planned this morning.

It's 7am in the patrol hut and already the talk

is of the snowpack - how much snow there was in the night,

the temperature, the wind direction...

It all adds up to the reason why we're here.

We're going to fight avalanche with avalanche.

Controlled explosions are used to create small avalanches

rather than let the snow build up into something much bigger,

more unpredictable and more deadly.

So we're right at the edge of the snow ledge here.

The snow patrol are making three holes down into the snow,

they're going to drop three explosives down into those holes

to detonate and cause an avalanche

and then they're going to get out of here rapidly before that

happens, which is exactly what I'm going to do now.

Wind has caused snow to build up into a dangerous overhang

called the cornice.

This one is unstable and could fail

at any time right onto

the piste that is running directly below.

The team need to remove the snow now

when the ski lifts are closed

and we know there's nobody underneath.

We are about to witness the power of an avalanche.

LOUD BLAST

My heart's racing!

If there was anyone down the bottom of that, they would be toast.

Absolutely incredible.

You could see there was so much snow up there with that ledge,

now it's all gone - all you can see is rocks.

There's only one place it went. Down as an avalanche.

I've just witnessed my first avalanche and it was breathtaking.

Today, we have had an insight into the power of the avalanche

and also the ingenuity of the human beings who live with the threat.

The machines that make the slopes safe

and the technology that can save you if the worst happens.

Every second counts.

Because of this, avalanches where people get hurt are quite rare,

so be careful, not afraid.

The mountains are a wonderful place.

Next time, on Fierce Earth,

we discover the awesome power

of the landslide.

Leah goes out with the crews

trying to save our cliffs

from slipping into the sea and I go deep underground to

witness the massive caves hollowed out in the rock beneath our feet.

That's amazing! Wow!