Thursday 13 October 2022

Avalanches, Beacons and Being Searchable

1. Learn How to Interpret the Avalanche Forecast. Don't get avalanched ......



The Avalanche Danger Scale uses five progressively increasing danger levels: Low, Moderate, Considerable,  High and Extreme. It indicates the likelihood of avalanches, how they might be triggered and recommended actions in the back country. However, the wording is very brief and does not include a meaningful indication of risk. Below is an explanation of each danger level, including the transitions between levels, signs of instability at each level and the implications of slope angle, aspect and elevation.
Understanding the SAIS forecast as acting on it could save your life
Low
Travel is generally safe. The snow pack is well bonded and natural avalanches will not be seen except for small sluffs on extremely steep slopes. Human-triggered avalanches are unlikely except in isolated locations in extreme terrain. The danger will usually be from wind-driven snow in gullies and chutes or deposited across very steep open slopes near ridge lines. Ski or board one by one as smoothly as possible without falling if you suspect the formation of wind slab. Be aware of shaded, north to east aspects where the danger may be transitioning to Moderate. There are few fatalities at this danger level.

Moderate
This is the most difficult danger level for back country skiers and boarders to assess snow stability. Many of the usual indicators such as cracks, settling, whumpfing and signs of recent avalanche are absent, especially at the lower end of the moderate level. Key indicators are any recent snowfall, and wind deposition. Snow pack tests may help assess stability.

Conditions are generally favourable for travel providing routes are chosen carefully. The snow  pack is only moderately bonded on some steep slopes. Areas of danger are usually restricted to certain types of terrain such as bowls and gullies. The altitude, aspect and type of terrain where danger can be expected are usually detailed in the Avalanche Forecast. Remote triggering is unlikely, so you only need to be concerned about the steepness of nearby terrain features.

Human-triggered avalanches are possible. Ski or board carefully, one by one, in suspect terrain and avoid high loading of the snow pack by spreading people out on the uphill track. Carefully evaluate the stability of very steep slopes (steeper than 35°) and aspects identified as potentially dangerous in the Avalanche Forecast.

Be especially careful if the higher elevation band in the forecast, or the danger on other aspects, is Considerable. There is a significant difference in instability between Moderate and Considerable. Don’t get sucked onto higher, steeper and more dangerous slopes. Although naturally triggered avalanches are not expected, ice climbers should watch out for the sun warming steep collection zones above their climbs. If deep-slab instability due to a persistent weak layer is mentioned in the Avalanche Forecast, you need to pay careful attention to the terrain. Avalanches from such a layer are not only likely to be large and extensive, they are completely unpredictable. Unless you have specific local knowledge, keep off large open slopes at this danger level if the forecast warns of a persistent weak layer.

29th March 2013 using the older SAIS Graphic for localised considerable hazard
Persistent Weak Layer March 2013

Click pics to enlarge

Large Slab Triggered off persistent weak layer 30th March 2013
Fatal Avlx x 1 Skier Glencoe
Considerable
Conditions have become much less favourable. The snow pack is only moderately or poorly bonded over a much larger area of the terrain. Human triggering is possible by a single skier on steep slopes and aspects mentioned in the Avalanche Forecast. Remote triggering of avalanches is possible, so the maximum steepness of the slope above you should be used when deciding if you want to continue.

Instability indicators mentioned in Moderate danger above will likely be present. Back country touring at this danger level requires good route finding skills, and experience in recognising dangerous terrain and evaluating slope stability. Keep to slopes of less than 35°, especially slopes at the altitude and aspect indicated in the Avalanche Forecast. Remember that remote triggering is possible. Typically the scree fans at the bottom of gullies start out at around 30° and the slope steepens as it gets higher. Keep off such slopes at this hazard level. The remarks about persistent weak layers in the previous section on Moderate danger level also apply to this danger level.
New SAIS graphic as stripes for localised "considerable"

Reports such as the above showing stripes as areas of  localised "considerable" risk  to North and South within a moderate NW to SW aspect and considerable risk NE to SE. This is the sort of thing that it's easy to become complacent about as its a common feature of the Scottish winter. You might very obviously if you have any sense, stay well clear of the NE to SE aspects but wander into a high risk situation on descent on the N to S aspects.  The majority of avalanche incidents in Europe occur in these moderate to considerable forecast days as they occur most frequently in the season and folk become complacent (the familiarity heuristic) and that's why route choice approaching a climb and thinking about descent options prior to leaving and during a trip as wind and weather change should become part of your thinking.

High
Conditions have become dangerous, most often as a result of significant amounts of new snow, snowfall accompanied by wind or the snow pack becoming isothermal and threatening wet-snow avalanches. The snow pack is poorly bonded over large areas and human triggering is likely on steep slopes (steeper than 30°). Remote triggering is likely and large natural avalanches are to be expected.

Stay on slopes that are flatter than 30° for any part of the slope and be aware of the potential for avalanches from slopes above. If you do decide to walk ski or board on less steep slopes, be very aware of the surrounding terrain to avoid inadvertently crossing the bottom of steeper slopes or cutting down a steep convex rollover.

Usually this level of hazard is only present for a few days at a time. The smart back country traveller will stay in simple terrain until conditions improve. If you are caught out on a multi-day trip you may have to dig in and wait for travel conditions to improve and the avalanche danger to lessen.


These stripes in the avalanche forecast. My take is to think of them as landmine strips blown by the wind, lurking in eddies from cross loading when the wind blows across as well as down or over a slope, the colour of them is the sensitivity of the pressure plate to you the trigger. If there are enough of them the explosion will propagate setting of others, or if the surrounding slope is weak enough then it will slide with it. As you can see there are areas of High on slopes with a localised "considerable" and a"considerable" risk to the South.  A lethal combo of  narrow safe travel options making for events that will take lives if you don't tread warily and navigate with extreme care.

Extreme
Extreme danger levels are rare in Scotland as usually this level is associated with buildings and roads or alpine villages under threat, and usually the result of unusually large amounts of new snow. The snow pack is weakly bonded and unstable. Numerous large avalanches are likely. The weight of the new snow can trigger avalanches on layers buried deep in the snow pack. Natural avalanches can release on slopes of less than 30° Back country touring is not recommended and often impossible. Avoid all avalanche terrain and keep well away from avalanche path run outs.

Avoid Groupthink
In psychology "Groupthink" or "Risky Shift" behaviour is well known in groups and most of us will be aware that we have given in to it or even encouraged it. I strongly believe that in avalanche incidents in Scotland this groupthink or risky shift has become the biggest education issue and maybe why we see large group incidents or group events as occurred in the Cairngorms when two separate groups were avalanched last winter. Much has been made of the quick response from folk training in the corrie who helped.  And good on them. What I am about to say is not a reflection on these helper folks choices, as I am sure they stayed in safe terrain.  The  "however" bit though is that just by being there and numbers increase with lots of MRT's training, and groups under instruction, then a larger "Groupthink" takes place. Groups less experienced or not under instruction maybe feel safe, what McCammon labels  as Social Facilitation.  I would call this a  "risky shift". It's often this way in the climbing and skiing honey pots such as the Northern Corries where folk gather. Aonach Mor or ScRL in Glencoe are other places. Even if the waggon wheel of death shows Red on these slope aspects, they are still the places to be seen by the instructor masses who are now at the height of their annual gatherings with paying students. These are the places instructors are familiar with, and therefore where less experienced folk feel safer with an apparent safety in numbers. They maybe went there when they were on a course. Group thinking on a large scale perhaps.

Better minds than mine have already written about risky shift and here's an excellent article on it The Risky Shift Phenomenon and Avalanches. This kind of stuff has been getting applied to avalanche instructor training for a while by AAA.  Do current winter mountain training schemes  include enough if anything on this sort of thing?  I put this as a question, as I am certainly not in a position to know, and maybe it is already covered. What I do know is that there is nothing that can change the pretty piss poor odds if buried and that pretty universally all of us involved in avalanche education are trying to jump forward and get to "no rescue".

No matter what we do, mountains and people are unpredictable. As a keen off the piste skier I have to accept that luck is also in there as well, as on good snow days I am first in the que and having gone through the forecasts, stability tests you are only left with how the snow feels under you ski's and gut instincts. Sometimes it's a very subtle thing where in the morning it feels wrong, and by afternoon the snow "feels" safe.  I don't know how the feck that would stand up in court! I also know its taken 40 years and I still can't always be sure it all won't go tits up one day. I also know that it pays to voice your opinion when in a group, and make your own choice, not getting swept along by the group and it's most vocal leader. Beware Risky Shift!



"Destiny is a good thing to accept when it's going your way. When it isn't, don't call it destiny; call it injustice, treachery, or simple bad luck"   Catch 22 by Joseph Heller

For backcountry travel, side stash/off piste, or indeed anything out of ski area and uncontrolled, always carry the three essentials of transceiver, shovel and probe and do a pre depart group beacon test and practise.



If you need an airbag you have fucked up but might survive. If you need your transceiver you have fucked up and probably won't!

2. Get a Beacon, Shovel and Probe. Some Transceiver Observations:

These 3 antenna beacons are all good purchases, but like all technology when used for scenarios that are not simple then their effectiveness is challenged and quirks come out. Only realistic practise with the beacon you own will make you the user aware of what these are, and work arounds.  What this means is practise and realistic scenarios to challenge you the searcher. That's what Beacon training parks are there to help you with. I have attempted to be non biased but declare a conflict of interest as I am an Ortovox retailer.

Auto revert or random transmit from rubber-neckers is the curse of the avalanche search. Be aware of it when on a long search, and be aware if its pre set on or you have to activate it as part of the pre trip beacon check.


I do a special offer of the pro level "Diract" and "Diract Voice" to SMR and Ski Patrol. For professionals I recommend folk wanting an upgrade to consider this very advanced Beacon. It takes you straight to the victim, has a very reliable "mark" feature and a host of other built in pro features such as actually displaying visually where each victim is with distance, a longer range (55m) than other digital beacons (most are 25m) and of course the smart antenna that gets you found faster. Also incorporated is a Recco reflector inside as back up and the smart antenna to get you found.

click over image to read

Ortovox Diract Transceiver/Beacon

3. Get some Training and Practice Digging


Learn how to interpret the days SAIS forecast and some basic snowcraft

Learn how to use your transceiver effectively

Learn how to find, digout and take care of an avalanche victim
Learn how to dig effectively as time is oxygen and your shovel is the key to living or dying. Can you resuscitate your friend or provide first aid if they are injured ?


4. Recco. Mountaineers are not Searchable - most of the time ...............

Don't get buried! But if you do you want to be searchable 
and found FAST!
Recco is another important part of the organised rescue strategy. Education and avalanche avoidance is primary, being found early by companions if it goes wrong is vital and prior practise makes this work. Organised rescue requires a triple response: Dogs, Recco and Probe Lines. Until now Scotland has only been able to apply two of the three unlike alpine rescue avalanche search where for years all three have been used. Survival is time critical. Much has been made of trauma being the main factor in poor survival in Scottish avalanches. Largely based on recent tragic avalanche incidents where trauma has clearly been the dominant factor.

These anecdotal observations and opinions make easy it to forget the victims where triple "H" syndrome has been the killer of which there have been many over the last decades. Anecdote though is not enough, and there is no recent data set from necropsy studies in Scotland, (if there is its not readily available). One thing is sure, being searchable and getting found quickly increases survival. Some Scottish MR teams already have Recco as part of their search strategy (Tayside, Glencoe, Cairngorm MRT's) and Cairngorm, Glencoe and Nevis Range Ski Patrol. A good thing. I can imagine nothing worse than a victim recovery delayed because a search team did not have a detector and the victim is found to have either a Recco reflector or a harmonic on them. Recco is of course for "organised rescue". Everyone including Recco and the clothing manufacturers endorse the view that not getting avalanched through education and training is better than needing any search devices which may be too late. However, in the real world shit still happens and unless someone is "searchable" a rescuer cannot find them readily even if the poor victim has bottomed out of the survival curve. We should not forget Robert Burnett's remarkable 22 hour survival in the Southern Cairngorm's. All victims surely deserve the benefit of the doubt and rescuers throwing all resources at an attempt for a live recovery.
Small sticky reflectors that can be attached to boots or helmets
As "off piste" and "Backcountry" skiing grows in popularity there is every reason to imagine that being more searchable can save lives.  Nothing can replace education and prevention, or fast effective companion rescue with beacon, shovel and probe, but as ski patrols and MR teams take up Recco and the reflectors can be bought and carried then the chance of getting found alive by organised rescue if on scene quickly increases. I would recommend two reflectors to mountaineers, One front top and one back bottom.
Sewn in reflector


So Recco is here in Scotland and its great to see the take up by enlightened Scottish rescuers adopting alpine best practise. Who knows when Recco will save a life, but if it does it's job then its been donation money well spent.
Live recovery of a victim located by her Recco reflector from 3m burial
Glencoe Ski Patrol doing a precautionary combined 457mhz transceiver search and Recco harmonic search. The R9 detector searches both, and at close range can find many other harmonic devices such as mobile phones.

The reflector for Harmonic Radar or RECCO