January 16, 2016 – Skyscraper Mountain

January 16, 2016 – Avalanche Accident on Skyscraper Mountain

An avalanche fatality was confirmed at this site on Jan 16, 2016:

jan 16 2016 MAP

Jan 16, 2016 – Avalanche accident site

Human triggered avalanche- HS-AR-D2.5R2-O

Skyscraper Mountain

SSE aspect (160°), cross-loaded slope and features

Triggered at 4200?

Slope angle at crown = 43°

Estimated size: 6-8″ deep consistent across crown X 120′ wide X 600′ run

Debris pile 12′ deep X 185′ wide, victim buried 7.5′ deep

Victim was traveling by snowshoe, climbed Skyscraper Mountain, triggered avalanche while descending by snowboard. Victim was traveling with one other partner, neither were wearing avalanche beacons. Avalanche likely triggered above rider. Lack of avalanche beacons, and the depth of the burial contributed to a long burial time, approximately 45 minutes.

jan 16 2016 avy

Jan 16, 2016 avalanche accident site on Skyscraper Mountain, HS-AR-D2.5R2-O
jan 16 2016 crown

Average crown height 6-8″, 1F slab over F facets weak layer (large grain size difference) over F+ facets bed surface.
jan 16 2016 debris 3

Left debris pile is old natural avalanche from Jan 2. Right debris pile is the Jan 16 accident site.
jan 16 2016 debris 2

Large debris pile, approximately 12 feet deep
jan 16 2016 debris

Hard slab chunks, P hardness, up to 3 feet thick. This avalanche had a consistent crown depth of 6″, but pulled out a much thicker wind loaded/deposited slab. Classic Persistent Slab triggered at shallow point.
Jan 16 2016 crown profile

Crown Profile Jan 16, 2016 Avalanche Accident

Weak layer

 

JAN 16 2016 AVY ACCIDENT from HPAC on Vimeo.