2005-2006 Season Incidents
Date: March 18, 2006 :
Location: Chute Out, Ellery Bowl, Tioga Pass:
Incident: 1 triggered cornice break, 1 caught.
A lone skier fell into Chute Out at Ellery Bowl on Saturday, March 18th after breaking a cornice. He suffered extensive injuries, but is recovering. The complete incident report is available here.
Date: February 1, 2006 :
Location: Mt. Walt, Blacksmith Creek, Bridgeport
Incident: 1 triggered, 3 caught, 1 fatality
On Wednesday morning, Feb. 1, 2006, three off-duty Mammoth Mountain Ski Patrollers, CJ Pearson, Johanna Carlsson and Joshua Feinberg, left the Twin Lakes trailhead around 7am with their destination being Mt. Walt. Mt. Walt is accessed from the Blacksmith Creek drainage, which is west of Twin Lakes in the Bridgeport area.
After an inital climb through heavily timbered northern slopes, the skiers reached an open area that began at approximately 8,600'. At this point they began switch-backing up a 35 degree east-facing slope. The slope angle gradually increased as they entered a stand of scattered whitebark pine. This area presented tricky skinning conditions due to an icy surface crust and complex terrain. Near the top of the whitebark pine glade, the group stopped to assess their route across a shallow wind-loaded gulley. It was necessary to cross the gulley in order to attain safe terrain on the ridge. This gulley was approximately 125' across and the decision was made to cross the slope one at a time from what seemed to be a safe location in the trees. At this location the slope angle was approximately 40 degrees.
Josh, the first skier, used two small trees in the gulley as kick-turn anchors and gained approximately 15 more vertical feet before beginning his final traverse toward a break in the slope angle on the ridge. Josh was about 5 to 6 ski lengths from the ridge when he triggered a small slab avalanche (4" crown) and was carried downhill a short distance - approximately 20'. At this point, a deeper (18" crown) slab avalanche released and propagated approximately 400 linear feet along the lee side of the ridgeline above and below them.
All three skiers were caught in the slide. CJ managed to hold on to a tree while the avalanche flowed past him. Josh was swept downslope approximately 800 vertical feet through the throat of the gulley and onto the slope below. Josh was partially buried in the main portion of the debris with his head approximately 10" below the snow surface and the edge of his pack at the snow surface. Johanna was swept approximately 600 vertical feet through the whitebark pine glade, onto the open slope on a separate lobe of avalanche debris. Johanna came to rest on the snow surface and was not buried.
CJ began a beacon search for Josh and Johanna, initially picking up a weak signal that led him to the southern lobe of the avalanche debris. At this point, he picked up a stronger signal and could see Johanna on the surface below. He skied to her and assessed her condition, finding her semi-conscious. CJ turned off her beacon and continued the search for Josh. He followed Josh's signal and saw the edge of his pack exposed near the toe of the northern lobe of the debris. He uncovered Josh's head and upon clearing his airway, Josh began breathing again. He finished digging Josh out of the debris, at which time Josh's condition seemed to be improving.
CJ returned to Johanna's location, re-assessed her condition and then moved her down and across the slope to a safer location. At this point, CJ left Josh with Johanna and went to get help. A rescue involving Mono County Search and Rescue, Mono County Sheriff Office and a National Guard Blackhawk helicopter took place over the next 4 to 5 hours. Johanna was flown to Fresno. CJ and Josh hiked out under their own power with Search and Rescue personnel.
The avalanche released on northeast to northwest aspects at 9,600 ft. Doug Chabot and myself returned to the scene the following day. The crown was not visible due to wind loading in the shallow gully. The avalanche ran 1,600' long, 900' vertical and was 50' across at the toe of the avalanche where there was between 8' and 10' of debris.
The slope failed on a 2 cm wind crust of knife hardness. Total depth was 215 cm.
There is an MPEG movie that was shot by Doug Chabot at the scene of the accident the following day that helps to show the terrain a bit better as well. We will put that online ASAP. (The file is 19mb).
The photos of this incident will also be placed back in the Gallery soon.
Date: March 18, 2006 :
Location: Chute Out, Ellery Bowl, Tioga Pass:
Incident: 1 triggered cornice break, 1 caught.
General incident
December 17, 2005. Time: unknown. Place: Hammil Bowl
Number caught: 1 in two separate incidents
Number buried: none
Number killed and injured: none
Narrative: For a complete narrative, click here.
Avalanche
Snow conditions: from narrative and personal observations of wind redistribution of snow from southwest winds, the slope was getting windloaded. The wind deposited snow was falling on three or four inches of recrystallized snow from the Dec. 8 storm.
Crown depth: Avalanche #1: 6 inches. Avalanche #2: 10 inches
Slab width/length: Avalanche #1: 50 ft width. Avalanche #2: 50 ft.
Avalanche Type (HS, SS, WS, etc.). Probably soft slab
Starting Zone (Slope, Aspect, Elevation): 20-25 degrees. N to NE aspect. 10,200 to 10,400 ft.
Path length: Avalanche 1: 150 ft. Avalanche #2: 300-400 ft.
Path-relative class: not known
Trigger: human, for both avalanches
Ski cut?: Avalanche #1, no. Avalanche #2: triggered while skiing (riding).
Group Dynamics
Familiar with terrain?: YES
Mixed gender group?: not known
Sense of commitment or reaching objective: Party retreated after first avalanche occurred.
Level of training within group: not known
Was there a leader?: not known
Pre-existing tracks?: Yes, visible in most places except where wind loading had covered tracks.
Rescue gear? Trained in its use?: not known
Any formal snow evaluation?: not known
Any “hasty” snow evaluation?: not known
Any discussion of conditions?: Not known
Danger Signs?
Recent new snow/SWE deposition?: Last storm was December 8 with 3-5 inches accumulation.
Wind loading?: YES
Avalanches visible on other slopes?: not known
Whoomphing, cracking, other signs of instability?: Yes
Avalanche advisory at the time?: Yes, the danger rating was low to moderate
Terrain trap?: no
