Steamboat & Flat Tops

Avalanche

Jake Castle · Jan 29, 2017 · Steamboat & Flat Tops

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Weather

Sunny, Clear, Calm wind. Air Temp -8C.

Snowpack

Soft Slab above surface hoar. Slab was composed of 26cm F hardness decomposing precip. particles 1-2mm grain size over 21cm 4f hardness facets 1-2mm grain size. Surface Hoar at 47cm was 5mm+ large grains. SH was widespread across aspect.

Avalanche

R2 D2, Skier Triggered. Avalanche was triggered remotely from lower angle terrain 20M above convexity near ridge top. Failure occurred on very large grain surface hoar layer. Crown fracture measured approximately 60M and was on about 40 degrees slope steepness at the point of initial fracture. We dug a 100cm pit approx 1M above the crown to test SH layer at 47cm. CTE 6 SC, ECTP 12 SC, PST 15/100 End down 47 We were able to trigger 2 additional test slopes resulting in D1 persistent slabs on the same layer from above several nearby convexities on the same aspect on our way to our safe exit line.