BC Zone Observation Report
Monday, January 29, 2018 at 12:00 AM
Wolverine Basin / Right Chute ridge
warm day, no signs of wind
Went to find the threshold for where persistent slabs remain a problem. We know that our eastern end of our zone is so weak that below treeline in the upper brush creeks and cement creek areas, the generally too weak to propagate a crack. We also know that around Pittsburg persistent slab structures and still exist as evidenced by last Thursday’s remote trigger, and two known skier trigger slides in the Purple Palace area today (Monday January 29th). So we went to the in-between zone, closer to town, right on the margin of the snow belt. Below 10,000′, we found rotten, faceted, trap door conditions on north through east slopes. Facet sloughing on slopes ~40+ slopes. Crusted on southeast aspects. 10-11,000′ seems to be the sweet spot for the lower margin for remnant persistent slab concerns. The slabs are losing strength, but still propagating in ECT’s and PST at around 10,000′. Above 10,000′, there’s no question that a hazard remains if you’re on a steep slope with wind consolidation from old drifting or steep sun-settled slopes just south of east. At 10,900′ on a slope angle in the high 20’s, we triggered a 40′ wide collapse as we neared an east-southeast facing ridgeline, complete with shooting cracks.
triggered several small loose facet sloughs on steep slopes below 10,500′ on north through east aspects.
AS / c
Wolverine Basin / Right Chute Ridge
easy to push facets on slopes over 40 degrees
persistent slab hunting, close to town, not in the deep zone, not in the shallow zone, but looking for the margin between. It seems to exist above 10,000' on NW to E aspects.