Accident Report
Saturday, December 3, 2005
No Name Bowl /
Report by
Brett Kobernik
Location:
No Name
Bowl on the east side of the Park City Ridgeline
(Click
here for a diagram of the slide path)
Accident Summary:
Four
skiers were caught in a large avalanche on Saturday, December 3rd,
2005. The skiers had decided to go to No
Name Bowl on Js recommendation. They
were looking for good powder skiing. The
group had skied two runs successfully and returned to the top. At around 12:45 pm they then traversed
farther out to the north to ski where there were still fresh tracks. J, R, and JN skied
the slope and regrouped where they thought they were clear of the slide
path. RR was two or three turns into the
bowl when it fractured. He went for a
ride as the 600 wide avalanche started down hill. It overtook the other three skiers and all
luckily only ended up partially buried or mostly buried.
Rescue Summary:
Two of
the victims were buried deep enough that they were not able to dig themselves
out. The other two were able to deg
themselves out then help dig out the rest.
They regrouped by about 1:00 pm to decide how to evacuate the area as
they had lost most of their gear including skis, poles, and some of their
clothing such as gloves, etc. They then
called for help and were evacuated by helicopter by 4:45 pm.
Avalanche Data: (Click
here for crown profile)
The
avalanche was classified as HS-AS-D2-R4-G.
It was on a northeast facing slope, 36-38 degrees in steepness, with the
starting zone at 9200. The average
depth of the crown face was around 20 with 14 at the shallowest and about 34
at the deepest. It was about 600 wide
and ran about 1200 vertical. Weak
faceted snow from early November was the weak layer with a near pencil hard
slab on top of it with some lighter density new snow on the surface. The lookers (gunners) left side of the bowl
had a shallower snowpack and weaker facets then the
highest area of the starting zone. Its
assumed that this was the reason they were able to ski two laps each before
going over to ski where the snow was weaker, causing the collapse.
Weather History: (Click here for
seasonal weather history charts)
The
Wasatch started receiving snow in late October and early November which then
underwent near surface faceting. A
series of storms started just after Thanksgiving which formed the slab over the
weak layer.
Comments:
All of
the skiers had near 30 years of backcountry skiing experience each except J who
still had around 10 years experience.
When RR was interviewed, he said that they were aware of the weak snow
near the ground and that No Name Bowl was prone to avalanching. Group dynamics played the biggest role in
this accident as the lure of fresh powder and having fun with friends overrode
their avalanche hazard decision making.
This is a common theme when experienced backcountry travelers get caught.