Two skier triggered slides at Lionhead

Ski Hill
Lionhead Range
Code
SS-ASc-R1-D2-I
Elevation
8000
Aspect
NE
Latitude
44.70160
Longitude
-111.29300
Notes

Dave and Doug of the GNFAC intentionally triggered 2 slides on Ski Hill on Lionhead.

We parked sleds and Doug took off along the rollover to skiers right and triggered a slide from 75’ away. The slides broke under the 8-12" new(er) snow that was on top of the 1' deep layer of sugary facets/de depth hoar Size was about 100’ across and 150’ slope distance. Whumpfing, cracks. ECTP3 in our pit. Dave then took the lead over to the skiers left slope and got the far end of it to go with a whumpf. Same depth, same story, but this was bigger: estimated about 200’ wide and 3-400’ slope distance. ECTP2.

Number of slides
2
Number caught
0
Number buried
0
Avalanche Type
Soft slab avalanche
Trigger
Skier
Trigger Modifier
c-A controlled or intentional release by the indicated trigger
R size
1
D size
2
Bed Surface
I - Interface between new and old snow
Problem Type
Persistent Weak Layer
Slab Thickness
30.0 centimeters
Vertical Fall
200ft
Slab Width
150.00ft
Weak Layer Grain type
Depth Hoar
Weak Layer grain size
4.00mm
Weak Layer Hardness
F
Slab Layer Grain Type
Precipitation Particles
Slab Layer Grain Size
2.00mm
Slab Layer Hardness
F+
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Multiple Avalanches
Advisory Year