Avalanche Initiation & Snow Mechanics – Continued Professional Development IFMGA

This week we have had the first winter snowfalls here in the Alps and I got the chance to meet up with Alain Duclos once again to discuss his favourite topics of snow mechanics and in particular crack initiation, weak layer collapse and crack propagation. It’s kinda comparable to my work as an engineer and fracture mechanics in weld and acceptable flaw size that wouldn’t result in weld failure for the design load.

Alain is an avalanche expert, responsible for road safety in the Haute Maurienne which is home to the Frejus Tunnel – a major freight and transportation link between France and Italy that is over looked by some impressive alpine terrain. Sadly, Alain is often called as an expert witness for avalanche accidents in the Alps.

survivors are generally surprised that the slope avalanched and often underestimate the slope angle.

This highlights 2 things. The ability to accurately gauge a slope angle, remembering anything above 30 degrees puts you in avalanche terrain while also considering overhead terrain & the fact that they were surprised means they were operating in a relaxed mode, perhaps due to failing to recognise they were in avalanche terrain or failure to assess the risk. Alain’s website data-avalanche is a ‘go to’ teaching, training, and reference resource for everyone to use.

There are 6 main criteria to review and assess for avalanche danger; the avalanche bulletin, slope angles >30º, recent avalanche observations, rising temperature & thawing, overloading due to wind accumulation / new snow / rain, and the possibility of a buried weak layer which a bulletin should highlight for well frequented areas.

There are 4 vigilance modes, relaxed, suspicious/cautious, alert & risk or gambling mode. It is clear that if you are relaxed and get caught in an avalanche, then there has been a failure in the observations made.

Play long enough in gambling mode and the statistics will catch up with you. However to complicate the matter further, Humans fall into 4 different categories for decision making traits, and at best only 2 of these types of people are likely to make conservative stand alone decisions (ref Powder magazine’s – The Human Factor 2.0).

Extract from Powder mag’s The Human Factor 2.0

To set the scene we were on the mountain after the first 30 cm snowfall of winter. The Alps has another hot summer and then a cold snap at the end of September brought around 1.5 m of snow and was followed by nearly 2 months of Indian Summer. Meteo France had not started avalanche forecasting and so digging a number of snow pits would provide valuable current information on snowpack stability. 

Usually I would have been skiing since September but with the new norms this was my first day on snow. We did a number of investigative snow tests between 2750 m and 2350 m on northerly aspects on 30-35 degree slopes. At each site 2 Compression Tests (CT) and a Propagation Saw Test (PST) were performed. For the first time all the tests yielded similar results – a weak layer lying just below the crust of the old snow surface yielding crack initiation, propagation and failure. Skinning around on the flat yielded a number of whoomps indicating collapse/failure of the weak layer. Its early days yet and no avalanche control has been done yet but it was definitely interesting to see whats going on right now.

Preparing the extended site for 2 Compressions Tests and Propagation Saw Test – circa 2.5 m long worksite
Compression Test 30 x 30 cm isolated column
Failure with Propagation Saw Test

I run 1 day avalanche awareness courses throughout the winter so don’t hesitate to contact me at rosshewittguiding@yahoo.com or phone/WhatsApp +33781287608 If you want to expand your knowledge and safety margins this winter.

Loschental Breithorn North Face

During a fortuitous meeting in the street with Ben Tibbetts a few weeks ago, he kindly shared the news that Jon Bracey ad himself had made a rare ascent of the Loschental Breithorn North Face…the seed was planted and I was psyched to go have an adventure.

Breithorn North Face on the right

With lockdown rules in France allowing professionally registered guides to train during lockdown, a controversial privilege that I am forever grateful, I had been training hard with some very long days on my bike. My legs were strong but I hadn’t worn crampons or been in the alpine for 2 months and was completely unacclimatised. James Clapham would partner me on the climb and conversely he was climbing fit, but looking after a toddler at home hadn’t left much time for cardio. It sounded like with some team work we would complement each others strengths well.

Off we went to Switzerland with heavy bags and light hearts, our spirits lifted by seeing something other than the sides of the Chamonix Valley after a month of lockdown. We planned to park at the roadhead in Fafleralp but to our dismay the authorities had closed the road for winter at Blatten, despite a distinct lack of snow. When the point of the trip was to catch up on lost time in the mountains, whats another 4 km added to the approach?! I usually hate walking as biking and skiing are such superior methods of transport, but after a month at home I loved just being outside and feeling alive in nature. The conversation flowed keeping our minds off the effort and we steadily gained height passing some steep icy grass, only to be forced to wage war on evil crusty faceted glacier snow. Our intention to climb and scope out the first pitch faded with the failing light and we settled on making our home for the night and the lengthy process of melting snow and hydrating.

We had a relatively civilised (for alpine climbing) 4 am ‘reveil’ and listened to the purr of the stove from the warm of our sleeping bags. After a quick breakfast, it was a pair of reluctant alpinists that swapped the warm comfort of our down cocoons for the frosty night air, knowing the quicker we got moving, the quicker we would get warm. The full moon that had risen as soon as we went to bed and kept out tent illuminated all night, set the moment we got going and plunged us into inky darkness. At the buttress James traversed off into the dark on a snow ramp with increasing exposure. The boys had warned us of compact rock with sparse protection and James did well to find a decent belay. As I followed the rope the precarious nature of the climbing and the unfamiliarity of mixed climbing was making itself felt. The route was pretty dry and it was more effective to crimp small edges rather than dry tool. The next pitch was lower angle and easier, but I found thin delaminated ice and only found one piece in a 60 m pitch that might hold anything. My belay was akin to Gogarth style affair in an attempt to distribute the load across multiple less than ideal pieces.

The next pitch was the main deal with steep rock plastered with blobs of neve, thin delaminating water ice making you wary and hard to spot protection arriving just at the right moment. James was in his element and quickly sent it. I followed absorbed in the delicate and interesting climbing feeling fully back in my comfort zone and trusting my feet. After collecting the gear from James, I led off and a short step was followed by the conspicuous elliptical snowfield we had spotted from below that joined the upper icefield. It was time to unrope and pick up the pace as we had a long day ahead.

At 11 am I made the last few metres onto the summit ridge and stepped out of the frosty shade and into the sunlight. The snow capped Alps stretched out to the horizons all around, a subliminal moment after a month of ‘confinement’. We paused for a moment to eat before continuing up the PD+ ridge and traversing the summit to the Biechglacier. The day was far from over with shocking snow conditions on the descent down the glacier and on the far side Biechpass but we got off the rough terrain in daylight which was a big relief for tired minds and tweaked ankles. As the forest trail gave way to the last 4 km of tarmac, the moon rose and we made the last section without headtorches.

James on the final steep pitch
Blasting up the headwall
Getting closer and lack of acclimatisation becoming apparent
James near the ridge
James arriving at the ridge and welcome sunshine
Savouring the sun and views at the exit of the North Face. Photo by James Clapham
A really fun PD+ ridge traverse led to the summit of the Breithorn. Bietschorn in the background. Photo by James Clapham
Photo by James Clapham
The final moves to the summit. Photo by James Clapham
The vistas and the world of light were especially nourishing for the soul after a month in the dark valley floor.
The Breithorn North Face centre profile and our bivi site at the col.
Thankful to reach the valley floor before dark with hideous leg breaking crust on the descent

The Best Runs of 2020

The best ski runs from 2020. We started the season down under. New Zealand must be one of my alternative spiritual homes, a place I’ve visited several times and feel completely at home. For skiing it’s like my Super Bowl. You may make all the moves and just be out of luck with high winds making you question the sanity of opening the outside door. But make the finals and on ‘The Day’ NZ will show you her magic and allow you play your A game. With @davejsearle we added a 700 m line to the Caroline Face, skied the 2nd known descent of Bowie Couloir and did another lap on the East Face of Cook. Back in Chamonix just as the season got good lockdown came and we had a wait of 2 months confined to our homes before restarting the season with a run on the Midi North Face to start the high mountain season. Dreaming of skiing during lockdown 2, hopefully it will be over soon.