Avalanche Forecasting & Danger Ratings Flashcards
7 cards from real ASC practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Avalanche Forecasting & Danger Ratings flashcards as text
Which avalanche problem type is associated with a weak layer buried deep in the snowpack that persists for weeks or months?
Answer: Persistent Slab
Persistent Slab problems involve a weak layer buried beneath one or more strong snow layers that can remain reactive for an extended period.
A 'Storm Slab' avalanche problem is most likely to occur during which period?
Answer: During or shortly after a significant snowstorm
Storm Slab avalanche problems develop during or shortly after heavy snowfall when new snow bonds poorly with the surface beneath it.
What characteristic best describes a 'Wind Slab' avalanche problem?
Answer: Dense, stiff slabs deposited by wind on lee aspects and cross-loaded ridges
Wind Slabs form when wind transports snow and deposits it as dense, cohesive slabs on lee aspects, cross-loaded ridges, and terrain features downwind of the prevailing wind.
The 'Wet Slab' avalanche problem is most commonly associated with which triggering mechanism?
Answer: Rapid warming, rain, or solar radiation that introduces liquid water into the snowpack
Wet Slab problems are driven by liquid water infiltrating the snowpack, reducing friction between snow layers and triggering large, heavy avalanches.
Which of the following best describes a 'Loose Snow' (or 'Point Release') avalanche?
Answer: An avalanche that starts from a single point and fans outward, involving cohesionless snow
Loose Snow avalanches start from a single point and fan outward downslope, typically involving dry, unconsolidated snow or wet surface snow.
What is a 'Cornice Fall' avalanche problem?
Answer: An overhanging mass of wind-deposited snow that breaks off and can trigger avalanches below
Cornice Fall occurs when overhanging masses of wind-deposited snow break off from ridgelines and can trigger additional slab avalanches on the slopes below.
How does aspect affect which terrain features are most prone to Wind Slab avalanche problems?
Answer: Lee (downwind) aspects and cross-loaded terrain features accumulate drifted snow
Wind transports snow from windward slopes and deposits it as slabs on lee aspects and cross-loaded terrain features, making those the primary locations of Wind Slab problems.