Ski Mountaineering Safety

Avalanche

The sky is blue. It’s the first day of good weather after days of snowfall. It’s bitterly cold. The snow sparkles in the sun. How soft and loose it was on the climb. New snow! Powder!

The pull up to the summit was hard work and now the team are all raring to go. Others already shout and whoop as they ski the powder below. “Come on! What are you waiting for?” So go for it! Ten meters in you glide in the lee of the ridge.

Beautiful! Magic! You shout with joy! Turn, turn, turn. Ecstasy…

‘WHUMM!’ Your heart misses a beat. A crack in the snow rips open. Fear grabs your gut. You slide out of control. All is confusion. Snow covers your face. You fight in panic. Too late! Avalanche!

Yet… all the alarm signs had been there to see…

Many, many accidents occur on days when the weather is pleasant: generally clear skies, little or no snowfall and light or calm winds. A high proportion occur just after new snowfall.

Human frailties rank high in the causes of avalanches. Ambition; itineraries; expectations; peer pressure. The perfect run… That virgin steeper snow beside those new tracks…Grab the chance now before the snow is skied out…

The Canadian Avalanche Association have shown that most avalanches are dry slab avalanches, with an average thickness of less than 100cm, 45% after just 10cm of new snow. Most are triggered by the victims or members of the victim’s party. The weak layer often consists of surface hoar, faceted snow crystals, graupel, or depth hoar.

The majority of accident avalanches start above or near the tree-line on lee (67%) or cross slopes where the wind has scoured across the surface (31%). Windward slopes account for just 2% of avalanches. Most avalanches (69%) start on 30°-40° slopes, typically on convex slopes, often with exposed rocks that cause stress concentrations, and often near the crest of a ridge. Only 6% happen on slopes of less than 25°.

The typical avalanche victim is male, in his twenties.

Ski mountaineering is a dangerous sport and precautions must be taken. Training in basic skills. Refreshing skills and knowledge every year. Specialised equipment, clothing, planning and assessment of snow conditions, to minimise or avoid risk.

Knowledge of snow and the factors affecting avalanches is indispensable.The chances of surviving burial in an avalanche diminish rapidly after the first five minutes of burial. The ability to locate and dig out an avalanche victim is essential and must be refreshed regularly by practice.

Essential equipment to enable immediate search and rescue to be attempted in the event of an avalanche burying a companion includes:

• an avalanche rescue transceiver,
• a lightweight metal snow shovel, and
• an avalanche probe

Transceivers are by far the most effective way of locating victims (44%), but do not prevent avalanches. A false sense of security imparted through wearing a transceiver might even contribute to an avalanche. They are an aid to rescue only.

Whilst it is important to learn and practice disciplined avalanche search and rescue, what is far more important is to avoid avalanches completely.

Defensive Mountaineering

Nearly all avalanche accidents can be avoided. Slab avalanches are the most common. 90% of people involved in avalanches trigger the avalanche that got them.

Always look for safe slopes when choosing a route. Decisions must be based on facts, not opinions, not a desire for excitement, not wishful thinking.

You must judge the likely stability of the snowpack at three key phases of the tour:

 Planning
 Route selection on the day
 Actual slope assessment

According to three key factors:

 Snow + weather conditions
 Terrain
 People

Make risk reducing decisions based on these facts to choose the route. These are summarised in the Planning Checklists.

If caught

SHOUT! – TRY TO ESCAPE – GET RID OF GEAR – TRY TO STAY ON TOP –  AS AVALANCHE STOPS TRY TO POKE THROUGH TO THE SURFACE – CLEAR SPACE AROUND FACE.

Alarm Signs

Continuously observe the snowpack and weather. Any of these alarm signs should alert you to increased risk

• The first good day after heavy snow
• Very cold when snow was falling
• Spindrift
• WUMM! sound
• Snow settling under skis
• Snow breaking up and sliding away at turns
• Cracks in the snow
• Lots of new snow on trees
• Heavy snowfall still falling
• Poor visibility so steepness of slope can not be seen
• Lee slope
• Convex slope
• Close to ridge crest
• Fresh snow ripples, dunes and other signs of wind
• Strong wind? Drifting? Plumes of spindrift
• Fresh avalanches, especially slab avalanches, which slopes and orientation
• Sudden rise in temperature

Two or more alarm signs together mean Avalanche Risk Factor 3 (Considerable) or greater.

Absence of alarm signs does not indicate a lower avalanche factor than forecast.

This guide is provided solely as an aid to mountain safety. Actual conditions can be other than they appear. This guide does not replace an individual’s responsibility to take account of all pertinent factors and to exercise due diligence in reaching decisions. Neither the Alpine Ski Club nor its office bearers accept responsibility for decisions taken by individuals or groups as a consequence of using this guide.

The information on this page is based on much valuable work done by the avalanche research associations and institutes of several countries, publications from Alpine Clubs in Europe and North America and on the work of Martin Engler, SnowCard & Faktorencheck, published by the DAV.

Further information can be obtained by exploring the literature and the Links page on this website.

Planning Checklists

Ask these questions during tour planning, at the time of actual route selection on the day of the tour, and when traversing individual slopes during a tour.

Check the three key factors that affect avalanche risk, snow+weather, terrain, people, at every step asking at least the questions in the table below. The answers to these questions and your own competence and knowledge determines your decisions.

There is no absolute standard. What might be safe for a highly skilled group that takes every precaution and modifies its behaviour and route according to the risks would be absolute folly for an inexperienced group quite unable to do this.

If in doubt, assume the worst case.

There is no such thing as zero risk. Hoar frost and graupel layers can persist in the snowpack all winter long with a correspondingly high slab avalanche risk throughout the winter even though all other factors might suggest otherwise. Check.

You are the rescue team

95% of survivors are rescued by their companions.

Before the Tour

Ensure that everyone has had practice searching with transceivers. It might be you who will be buried…

Do not assume that others are more competent and don’t need practice. Do not assume that you do not need practice.

Make sure everyone knows the plan for the tour and the reasons for the route chosen. They might need to find their own way out.

Be prepared for the possibility of an avalanche rescue. Organise your team before you set out.

A rescue will be stressful and take up a lot of time and energy. And you will have to deal with injured people.

Appoint possible search leaders.

Stress the need for discipline.

During the Avalanche

Observe avalanche and positions of victims in the avalanche. Note last seen positions with reference to landmarks (e.g. rocks, trees). This eliminates a whole section of the slope from the search. Spot clothing, equipment, body parts sticking out of the snow. Equipment, skis etc may or may not indicate victim’s position.

After the Avalanche stops

• Take charge. How many are missing? Count heads. Roll call.
• Appoint searcher(s) to find victims.
• Appoint rescuers to dig out and attend to victims.
• Appoint guard(s) to watch for further avalanches.
• People not involved in search to stay high in a safe region and keep their skis on.
• Determine safe way out of area.
• Switch transceivers to SEARCH. For most people, search is easier and faster with a digital transceiver.
• Switch off mobile phones to prevent them interfering with the search.

BEWARE OF SUBSEQUENT AVALANCHES. Whilst transceivers are switched off or to Search, there is a high risk that if someone is buried by a subsequent avalanche they will not be found in time. Guards must shout warning if subsequent avalanche occurs. Transceivers need to be switched back to TRANSMIT quickly.

Search

• SIGNAL SEARCH – to find the signal from the victim’s transceivers
• COARSE SEARCH – to come within 3 metres of the victim
• FINE SEARCH – to find the victim’s precise position.
• PINPOINT PROBING – to find the victim’s exact depth of burial and mark their position.

Control the search. Keep it progressing but not rushed. Digital transceiver searches tend to be easier. Searcher(s) start ski traverse and zig-zag search down path of avalanche downwards from level of party. If avalanche is large it may be more appropriate for two or more searchers to make parallel searches.

When signal(s) received, home in on the nearest (strongest) signal.

PRACTICE IN SEARCHING IS ESSENTIAL particularly for multiple burials.

Be disciplined. It may be better for just one person to do the search in a disciplined way than for everyone to rush in, some with transceivers still transmitting, and getting in everyone else’s way. If more than one person is searching, a separate person should direct and control the search.

LOOK OUT FOR VISUAL CLUES – AN ARM WAVING IN THE SNOW, JACKET, RUCKSACK, SKIS, AVALANCHE BALL.

This description refers to the use of BCA Tracker2 transceivers for illustration. Other transceivers can be used in a similar way but the operation of each may differ in detail from the Tracker2. Always refer to the manufacturer’s instructions on use.

SIGNAL SEARCH – Switch all transceivers to SEARCH mode. If the victim is more than 40m from you the Tracker2 will be silent. Using the Tracker2, sweep search from side to side down the track of the avalanche – traverses and kick turns – with the line of each traverse ending no more than 40m (20m for other transceivers—check user manual) from the previous line, until the Tracker2 starts to beep. Turn no more than 20m (10m for others—check user manual) from the edge of the avalanche track. Do this quickly without stopping but do not rush. If there is more than one victim, continue the Signal Search even after the first contact in order to discover other victims who may be near the other side of the avalanche and to avoid having to search uphill later.

COARSE SEARCH – When the Tracker2 starts to BEEP, you will be about 40m from the nearest victim. The range display shows how far you are away along the curved field lines from the target transceiver. The indicator lights of the Tracker2 point towards the victim along the field lines. If there is more than one victim to be found continue the Signal Search. If more than one victim has been detected, the multiple burial indicator lights up and the Tracker2 may indicate their directions more or less alternately depending on how fast each target transceiver sends its “beep”. Do not rush this. Transceivers “beep” at roughly 1 second intervals and the receiving transceiver can only display one at a time, so it is better to take your time in order to identify the victim positions accurately.

Follow the direction indicated by the lights to the nearest victim keeping the central light pointing to the victim. This might not be a straight line. As you come closer it locks to the strongest signal so only one victim will be indicated. If you are descending this should be the highest victim on the slope.

If weaker, more distant signal(s) are lost (the Tracker2 has locked to the strongest signal), mark the point (the Split Point) so you can return there later if necessary to resume the search. The line followed will curve since the Tracker2 follows the field lines of the victim’s transceiver. With a Tracker2, as you get closer, you will hear the beeps become frequent, until a rapid beeping indicates you are very close. Make sure that the range indicated is always getting smaller and is not increasing again.

FINE SEARCH – At about 3 metres from the victim, Stop, and do a grid search carefully with the Tracker2 close to the snow surface, preferably from below, facing uphill. The victim’s face might be buried below your feet so tread carefully. At 2 metres range, the Tracker2 direction lamps switch off automatically and only the range and audible ‘beep’ operate.

GRID SEARCH – Keeping the Tracker2 level, close to the snow, and always pointing in the same direction, move it with your hand in a grid-wise search, forward and back, side to side. As you overshoot, the range will start to increase so reverse the movement until a minimum is reached in both directions—forward-back, side-to-side. Mark this position in the snow.

DO NOT TRAMPLE ON THE VICTIM’S AIRSPACE

PINPOINT PROBING – At this minimum, probe the snow at right-angles to the snow surface at 25cm (10″) intervals in concentric circles until contact is made. Leave the probe in position to mark the victim. The probe will tell you the depth of the burial.

MULTIPLE BURIALS – If more than one signal is detected the Tracker2 may indicate both of them alternately and the multiple burial indicator lights up. If the victims are close together, the multiple-burial indicator flashes. Only the closest victim will be indicated unless you happen to be halfway between them.

Having found the first victim, if there are more victims buried and if you can’t turn off the transmitter just found yet, you can still find other victims by using the three circle search method to locate nearby victims. If others are available to dig, the lead searcher should continue the search whilst excavation of the first victim is proceeding. The Three Circle Method to find closely buried victims, searches in 3 concentric circles around the victim just found (this method works for all types of transceiver):

• Step 3 big steps to the side (3 metres or the length of an avalanche probe) from the victim already found. You can use the Tracker2’s display to confirm your distance from the victim.
• Search in a circle of radius 3m round the victim already found, slowly scanning the transceiver across the slope as you search. Somewhere halfway between the first and the next victim the Tracker2 may indicate both signals alternately and you can find the next victim. At this point it may help to move the transceiver with your hand towards the original victim and then in the opposite direction to confirm that a second signal has been detected. Go to the second victim. The Tracker2 will lock to the new signal when it becomes the strongest signal.
• If no victim is found on this search increase the circle radius to 6 metres, again using the display to confirm distance, and repeat the search.
• Should no victim be found again, increase the circle radius to 9 metres and repeat the search. The diameter of this circle (18 metres) approximates to the 20 metre search track interval used on the initial search.
• Fine search and Pinpoint Probe to locate the victim as before.

Should the Three Circle Search fail, or if there are more victims to be found, start a new Signal Search to find remaining victims. You may have to return to the Split Point in order to do this. Not all avalanches are simple plate slides. Frequently the path of the avalanche splits and victims can be carried to quite different positions thus complicating the search. Victims can be buried under the edge of the slide path, behind rocks, or in hollows.

Digging / Shovelling

Shovelling out a huge quantity of compacted snow to free an avalanche victim is time-consuming and extremely tiring. Digging a hole in compacted snow using only skis and ice axe is impossible so all members of a party must carry a lightweight metal snow shovel. Plastic shovels are unable to cut through the ice and concrete-snow of avalanches efficiently. Even with a team of practiced rescuers it can take more than 10 minutes to dig out a victim buried two and a half meters under the surface.

Digging is very tiring. Change the diggers frequently to allow them to rest between digs. If you are alone it might be better to leave a deep burial in favour of finding a shallowly buried victim who might then be able to help dig out the deep burial.

Keep your transceiver attached to your body. DO NOT LAY IT ON THE SNOW. Use it to confirm position of victim frequently.

Leave the probe in position to mark the position of the victim.

DO NOT TRAMPLE ON THE VICTIM’S AIRSPACE

Dig on your knees on the downhill side and dig towards the probe.

Start digging 1.5 times the burial depth away, 2m wide. This will allow space to roll victim onto side (recovery position) or onto back for artificial respiration.

Throw snow to side. When waist deep throw snow downhill.

If two diggers, start digging side by side and throw snow to side. Later, one behind the other, the uphill person throwing snow downhill for the other to clear. Change over frequently.

Dig in relays. As soon as a person tires, replace him/her. Change over frequently.

Slice the snow into blocks, don’t try to lever it out as the handle of your shovel may break making it useless.

If deep burial, dig tiers. Diggers on each tier remove snow dug from lower tiers. Deep burial rescues are slow.

CLEAR SPACE ROUND FACE AND CHEST FIRST

CLEAR SNOW FROM MOUTH AND AIRWAY

Resuscitate (mouth to mouth) if necessary.

If further search proceeding turn off victim’s transceiver.

Dig out victims that are close to surface first. It’s better to have one survivor than two corpses.

PATIENT CARE – Finding the victim and creating an airspace is not the end. They will be frozen cold and are very likely to need medical attention.

Keep the patient warm – get them off the snow. Insulated clothing, backpack, space blanket, multi-person bivouac shelter, sleeping mat, sleeping bag, tree branches … use all your resources.

Does the patient have life-threatening injuries (ABCDE)? Are you comfortable treating the patient in the environment you find yourself in? If not, then get ready to extract them to a safer place. You will need to check for common injuries and stabilise the patient.

EVACUATION – Depending on the situation and the seriousness of the injuries you might have to wait for an outside rescue team, stabilising the patient and keeping them warm, dry, fed and watered.

If the patient has a “useable” injury, evaluate if they are able to travel. Stabilise their injuries so they can travel safely and not make matters worse.

Can they travel themselves or do they need a sledge?

Know how to set up a sledge before you set out. Use all your gear to make a comfortable platform. Make sure the patient is secure.

Carrying a patient on a sledge takes a lot of your energy.

Helicopter Rescue

If you call for a helicopter rescue, help them by clearly identifying your position when you call.

Build a wind-sock so they can see the prevailing conditions on the ground.

Identify a flat landing area and try to mark it out, e.g. with branches.

Know the signals:

Never approach a helicopter. Wait for directions from the pilot.

Be prepared to build a snow shelter, if you have to spend the night outdoors.