An avalanche is a fascinating and naturally occuring phenomenon that is caused by unstable snow conditions. Since it is practically impossible to predict where and when the next avalanche will occur, significant amounts of information such as weather forecasts and avalanche forecasts are provided for the winter sports enthusiasts to aid their understanding of avalanche dangers and potentially prevent one from occuring.
The following avalanche information is not to be accepted as a set of instructions, it is designed merely provide guidance for those who wish to go off piste, and facilitate informed decision-making. It is also worth noting that avalanches are not the only dangers of off-piste: natural obstacles such as crevasses, buried rocks or cliffs are also potential hazards. It is highly recommended that you take a mountain guide whilst venturing into unknown territory.
Search & Rescue Equipment for Avalanches
The chances of surviving an avalanche are dramatically increased when the group are properly equipped with the standard avalanche equipment, and are trained in how to use it. None of the devices we have listed here will actually prevent an avalanche or prevent physical injury from occurring, but will assist in the recovery process. So what does the basic avalanche equipment consist of?
For anyone going off marked pistes, (including climbers, skiers, snowboarders, snowshoers and walkers); it is advisable that the following items of equipment are carried at all times:
Avalanche Transceivers (beacons)
Digital or analogue, these will send out a signal of where the body is located under the snow and/or assist in detecting the location of buried transceivers
Avalanche Probe
Portable (collapsible) probes are used immediately after a visual search to localise a buried victim, and give exact depth of the body
Snow Shovel
Shovels are essential for excavating the victim, quickly (speed is the name of the game) as the snow deposit is too dense to dig with your bare hands
Probes and shovels are often incorrectly viewed as less important equipment than transceivers, and purchased later. However, the French Avalanche Research Institute reports an exercise where sets of transceivers were buried 1 metre below the surface of the snow. Teams of five were given basic instructions on how to recover the 'victims', snow shoes, and different sets of rescue equipment. The following table shows how they faired (remember 15 minutes is the crucial time-frame where 90% of victims are recovered alive!):
Equipment
Time
Transceiver, Probe and Shovel
16 minutes
Transceiver and Shovel
26 minutes
Transceiver and Probe
50 minutes
Transceiver
60+ minutes
The search teams without complete sets reported problems either having to continually re-searching for the 'victims' as they dug (without probes); or had to resort to using their skis or snowboards and even their hands and to help them dig (without shovels).
Videos from Chamonix - Avalanche Search and Rescue
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Statistics show that in the event of an avalanche accident a buried victim has between fifteen to twenty minutes to be recovered alive. Although the emergency services are excellent at recovering those unfortunate enough to be caught in an avalanche, they cannot always be relied upon to mobilise within this small window. It is therefore essential to be able to carry out a self contained rescue.
For an introduction to avalanche search and rescue we spoke to British snowboard Instructor Roddy Clarke who has been working in the Alps forHAT mountain safety for six years and is a director ofPro Snowboarding Val d'Isere.
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Avalanche Transceivers
Avalanche transceivers work by sending / receiving electromagnetic signals on a frequency of 457kHz. There are many transceivers available in the marketplace using either analogue (older) or digital technology. Digital and analogue transceivers are compatible.
Analogue transceivers working in "receive" mode, convert the signals being transmitted by the "sending" transceiver from underneath the snow into sound waves. The receive signal is transmitted as a 'beep' which gets louder and stronger the closer the receiving transceiver gets to the emitting transceiver.
Digital transceivers interpret the same signal. A microprocessor converts the signals into visual data on screen, assisting with more accurate directional information. Digital transceivers are reportedly simpler to use than analogue ones.
The relatively high price of transceivers (around €300) should not deter you from purchase – at what price your or your companions’ lives? The cost reflects relatively low production numbers - ~60,000 units per manufacturer per year; high research and development costs as equipment has become more advanced; and that a high level of robustness and performance is expected from the manufacture process. An alternative is to rent equipment from a hire shop as you require it, however, as a rescuer in this scenario you are unlikely to be sufficiently proficient to be of help in detecting buried victims as you are unlikely to have practiced enough.
The following is a summary of transceiver tests conducted by French Avalanche Research Institute. Nevertheless, the best performing beeper is the one that you know and practice with!
Types of Avalanche Transceivers
Evaluation Criteria
ARVA 9000*
Barryvox
Ortovox F1 focus
Ortovox M2
Tracker DTS
Minimum Functional Range
**
**
***
***
**
Ease of Secondary Search Phase (Phase 2)
***
***
**
**
***
Precision during Fine Search Phase (Phase 3)
***
***
***
***
***
Ease of interpreting the signal
***
****
***
****
****
Detecting several transmitters
**
**
***
***
**
Using the instrument with gloves
***
**
***
****
**
Turning the instrument on
****
****
****
****
***
Turning the instrument off
****
****
****
****
****
Changing from transmit to receive
****
***
****
****
***
Changing from receive to transmit
**
***
***
***
***
Instructions
**
**
**
**
**
Transmitting Power
***
**
**
**
**
Source: 'a synthesis of subjective assessments' from: Sivardière F., 2000. Que Penser des ARVA de l'an 2000? ANENA, Neige et Avalanches, n° 92 - décembre 2000, p 9
*picture shown is the newer Arva A.D.vanced
Avalanche Transceiver Top Tips
Wear the transceiver as close as possible to your body. A transceiver worn just below the waterproof layer will be exposed if the layer is taken off when climbing and could then be torn off by the force of the avalanche. In addition, body heat will keep the transceiver and batteries warm aiding battery life.
It has been found that mobile phones interfere with the electromagnetic fields of a transceiver, mobile phones must be turned off at all times or in the very least kept as far away from each other as possible
Remove and dispose of batteries at the end of the season. Use new batteries at the start of the season, test and change frequently
Train at the start of and several times during the season, you can practise in your local park or even in the back garden. The stress of an avalanche is not the time to get the instruction book out! The search should almost be reflexive
Do not put a transceiver in your rucksack as this may be torn off by the force of an avalanche, and will result in only your rucksack being saved by the rescue services
Probing at right angles on a steep slope reduces the depth of snow to be dug (hypotenuse rule)
Remember that the transceiver is just a search and rescue device and doesn't enable you to go off-piste in poor conditions
Beginners often search with analogue devices at too high a volume. The volume should be reduced systematically to reduce the search area
If not in Europe, make sure that the local frequency is the same as that in use
Remember an avalanche transceiver is the only device that permits a group to perform their own search and rescue operation in the minimum amount of time
ABS Airbags
The most deadly risk during an avalanche is burial and the subsequent danger of asphyxia. An ABS airbag system attempts to reduce the chances of its victims being completely buried by working to keep the victim near the surface of a slide.
How does it work?
As a victim is caught in an avalanche they are tossed down the mountain either being pushed towards the surface of the snow or they become buried and are restricted from reaching the surface as the density increases and its lifting abilities decrease. The ABS airbag provides flotation, keeping the victim on the surface of the avalanche in motion. The ABS system is incorporated into a rucksack like device that is activated when the victim pulls a rip-cord at the start of their fall. Upon pulling the rip cord, a canister of compressed air inflates the two balloons within 2 to 3 seconds and the victim is kept on or near the surface of the slide.
In tests the ABS system has given very positive results. The Swiss Federal Institute for Snow and Avalanche Research in Davos, an independent world renowned avalanche research centre, played a leading role in the tests with the ABS-Avalanche Airbag System. Since its development, the Swiss Federal Institute for Snow and Avalanche Research has documented all the known accidents where the ABS system was used and figures are very encouraging. The Swiss Federal Institute for Snow and Avalanche Research reports the following statistics:
Of the 40 people that have been involved in an avalanche and used the ABS system, 39 have survived
5 people were fully buried even though their balloon had inflated
Despite the failure rate, the ABS avalanche beacon reduced the likelihood of complete burial from 39% to 16.2%, and
Lowers the mortality rate from 23% to 2.5%!
Avalung
An 'AvaLung' device is harness that's worn on the body to assist with breathing when trapped under the snow.
How does it work?
The AvaLung was developed by Black Diamond Equipment Ltd with the aim of prolonging survival time by at least an hour should the victim be caught in a full burial situation.
http://www.telemarktips.com/AvyAtkins.html
Weighing in at less than a pound, the AvaLung II offers critical oxygen intake that buys you precious time while buried under snow. Designed to extract air from the snow, it works to redirect carbon dioxide away from your oxygen-intake zone, reducing ice masking and CO2 poisoning of your oxygen supply. Unobtrusive over your regular outerwear, the AvaLung II is trusted by guides, avalanche control workers, patrollers and ski mountaineers worldwide. It's been proven to save lives in real life and supervised test burials.
There are a couple of technical challenges to users of the Avalung system. Firstly, with this piece of equipment the victim needs to get the mouthpiece, and keep the mouthpiece in his mouth whilst in the progress of an avalanche to ensure that he can use it one he comes to a stop. Additionally, is an air filtration system that is worn outside the users clothing and users need to make sure that they don't squash the breathing tube by their rucksak straps.
Read about real life experiences of the Avalung equipment here.
Avalanche Rescue Courses
So you’ve gone out and bought yourself the necessary goods to assist survival in the case of an avalanche if you don’t know how to use it then it can be virtually useless.
Henry’s Avalanche Talk (HAT) are a team of professionals, ski instructors and off piste guides who are passionate about the mountains, and are committed to providing the public with an insight to off-piste skiing and avalanche dangers.
Henry Schniewind, the company’s founder operates under the slogan of “Safety is Freedom”. At the age of 19 Henry had a lucky escape from an avalanche and has since turned his near death experience into something positive for people to learn from. Henry runs regular avalanche talks at ski resorts in the Savoie and Haute Savoie areas throughout the winter, educating people in how to ‘stay safe’ and ‘have fun’. In addition, Henry and his guides will give groups training on how to use their transceiver (beeper training), probe and shovels.
In addition, Mountain Tracks runs a series of avalanche courses during the winter season. The course is spread over 2.5 days and is ideal for those wanting to perfect their off-piste skills and knowledge. Mountain Track courses cover avalanches, avalanche terrain, decision making and rescue and are available in many of France's ski resorts namely: Tignes, Val d'Isere, Chamonix and Morzine
Pistehors website also provides a basic guide of how to search for avalanche victims using different search techniques. However, it is always best to make sure you have received appropriate training from fully qualified mountain guides before venturing out there on your own.
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