Black Tusk
Quick reportJustin Partridge · Dec 17, 2023 · Manning
Quick report
- Weather
- cloudy, warm, wet
- Ride Type
- mellowSlopes, openTrees
- Riding Quality
- terrible
- Snow Conditions
- crusty, heavy, wet
Another wet and warm day up high - it was about 0 degrees at 1950 meters with a light mist from the clouds. We hiked to and from the 6km mark on the Rubble Creek Trail and then skinned up to about the 2000m elevation mark near the Tusk. We dug a pit on a south aspect at 1950m, see snowpack section for details. We also got a windslab to let go on the lee side of a wind lip with a few kicks (see avalanche summary)
Snowpack
- Depth
- 88
- Obs Type
- point
- Site Aspect
- SW
- Test Fracture
- sudden
- Site Elevation
- 1950
- Ski Penetration
- 11
- Test Initiation
- moderate
- Foot Penetration
- 35
- Test Failure Depth
- 15
- Site Elevation Band
- alp, tln
- Surface Conditions
- newSnow
- Test Failure Layer Crystal Types
- other
Layer summary: top down : 15 cm of storm snow (4F) on top of Dec 10 rain crust (reported last week in a min from the same area). We found decomposing and fragmented particles just below this crust. About 1 cm below, decomposing fragments are followed by round, more consolidated snow 11cm above a large 6 cm crust from Dec 5th. Below this crust, rounds @ pencil for ~8cm followed by large crust complex with crusts and possible faceted snow which were difficult to observe. Below this to the ground are solid rounds from 1 finger to pencil Compression test yielded result in a sudden planer CTM 13 @ 15 cm BELOW Dec 10 crust probably due to the DF being poorly bonded. Another sudden planer was observed on very unscientifically hard smacks above the crust complex. The temperature gradient from surface to around 60 cm went from air @ -0.5 and warming to -2.8 @ 60cm from the ground with the Dec 10 rain crust possibly acting as an insulator.
Avalanche
- Run Length
- 14
- Slab Width
- 10
- Trigger Type
- skier
- Wind Exposure
- leeSlope
- Avalanche Size
- 1
- Slab Thickness
- 40
- Trigger Sub Type
- intentional
- Start Zone Aspect
- SE
- Vegetation Cover
- sparseTrees
- Start Zone Incline
- 35
- Avalanche Character
- wetSlab, windSlab
- Crust Near Weak Layer
- 1
- Number Of Avalanches
- 1
- Start Zone Elevation
- 1950
- Runout Zone Elevation
- 1945
- Avalanche Observation
- 12hrsAgo
- Start Zone Elevation Band
- tln
- Avalanche Occurrence Datetime
- 2023-12-16T21:30:00.000Z
I found an east-facing wind lip at 1950m while scoping out a descent route and noticed it cracking. I gave it a few good stomps and was able to get a 30-40cm thick slab to release. Admittedly, I was surprised at how far/deep this let go and thought that the same setup on a steeper slope with fewer trees would have caused a large slide. The slab propagated the length of the wind lip (about 10m) and slid easily on a planar surface. It ran about 10m, with the biggest chunks running about 5m. The bed surface wasn't a crust, the snow was probably 1F density and I didn't check the bottom of the chunks that slid. We suspect it ran below the Dec. 10th crust we found in the snow profile (see snowpack summary) but can't say for sure. Heads up around loaded features - don't fall for the moderate trap.