Iceline skier accidental

Activité

Ski

Nombre total de personne dans le groupe ?

5

Nombre de personnes entièrement ensevelies ?

0

Nombre de personnes partiellement ensevelies avec une respiration normale ?

1

Nombre de personnes impliquées ?

1

Forme du terrain au point de déclenchement

Régulier

Épaisseur de neige au point de déclenchement

Moyenne

Piège naturel

• Transition de pente ou replat

Travelling along the iceline skier’s route toward Yoho lake, we had noted widespread natural activity in steep alpine features on E and SE aspects. Crossing numerous moraine features through the day, we observed a soft wind slab forming on S/SE aspects, but it did not appear to be capable of propagating beyond the immediate trigger.

On the very last such feature before we would descend below tree line toward the lake, I failed to recognize two things:

1) the significantly more wind-affected surface at the top of the moraine feature

2) the fact that we were at a “corner” where the predominant aspect of Michael Peak shifts from E to S

In short, I let my guard down.

I stepped onto the slope, skins on, to make the short descent to a tree-line bench where we would transition and start descending to the lake. As soon as I did, my ski sank into a hole below a buried rock, hit some crust and pitched me forward onto my back. As I hit the ground, I heard the tell-tale whoomf and I was moving.

I was carried down the entire slope to where it transitioned to the bench. This transition was more abrupt than I had appreciated. As the snow in front of me stopped, it walled up like a wave. As I stopped, the snow behind me flooded over my shoulders and I took a deep breath, expecting things to take a turn for the worse. Thankfully, that is where it stopped. I was locked in the snow with my head and hands protruding, upright and unhurt, but completely unable to move. Luckily, the surface that the snow slid on was a hard, planar wind slab, so the ride was as smooth as one could hope for.

The wind slab that slid was far thicker and more consolidated than anything else we observed that day. In retrospect, there were clear signs that should have alerted me to that possibility. A safer route around the slope was readily available. Complacency was the root cause of the incident.

Other lessons:

1) even moderate transitions to shelf features should be considered dangerous terrain traps

2) on longer days, compliancy can creep in. Guard against it.

3) companion rescue practice should include a focus on clear communication in the first minutes after an incident