Incident

Avalanche: Argenta

BlakeSalt Lake
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Avalanche

Slab Width
15 m
Trigger Type
Snowboarder
Vertical Fall
381 m
Avalanche Type
Soft Slab
Slab Thickness
13 cm
Trigger Detail
Unintentionally Triggered
Start Zone Aspect
Northwest
Avalanche Problem
Wind Slab
Start Zone Elevation
3109 m

Today we dropped into Greaseball Couloir just north of the summit of Kessler Peak with the plan to ride out Argenta. On our way up, we dug a snowpit to test stability and found no deep instabilities in the snow structure. As we approached the ridge of Kessler we noticed a lot of wind coming over the ridge and depositing on the North face. We did some stability stomps and were unable to get anything to propagate or observe any shooting cracks. As we traversed from the summit of Kessler to the entrance of the line, we started noticing cross loading beneath the top of the couloir which was causing some strange wind pockets and small cornices. To test the stability of the cross loaded surface, I stood back and stomped at the base of a cornice about the size of a small fridge. The cornice broke and dropped onto the slope without causing any propagation on the slope below. Outside the cross loading, the majority of the wind gusts were coming up the couloir and depositing snow onto the East Face of Kessler. Which made us believe that there likely wasn't any widespread wind loading issues in the couloir proper.

I descended first and dropped into the hanging bowl, after making a heel side turn, an isolated wind slab broke loose below and above me which knocked me off my feet and took me for a ride. I was able to keep the majority of my body above the snow and was able to radio my partner that I was sliding with the debris. I made swimming motions with my arms and kicked my board to help keep me on top. After about 300 feet, I was able to slow down and stop, while the rest of the debris released below me. After regrouping, we descended the debris. The slope slid about 1,300 feet.

Mistakes / Learnings:

-Respect the wind. Even a small "manageable" wind pocket can break and carry you a long way in steep terrain with long runouts.

-Cross loading is serious. I had read the avy forecast and knew that wind was a problem, but I did not anticipate cross loading to be as obvious as a problem, as this is less common in the Wasatch. Lesson learned.

-Make a ski cut. I think I could have mitigated some hazard had I made a ski cut before dropping onto the hanging snow field.

Incident

Number Carried
1