Whumpfing refers to which event in snowpack conditions?

• A. Sudden planar crack
• B. Rapid thaw
• C. Surface crust formation
• D. Collapse of snowpack

Answer: (D)

Whumpfing is the audible signal that the snowpack is collapsing. When a heavy cohesive slab sits on a weak layer, added stress—like loading from new snow, warming, or a skier—can cause that weak layer to fail. The result is the slab dropping and the snow settling, often heard as a loud “whump.” This collapse indicates the snowpack is unstable and a release—potentially an avalanche—could follow with further loading. It’s not just a crack forming, nor a rapid thaw or surface crust change; those are separate processes. So the event described by whumpfing is the collapse of the snowpack.