powder クイズ

The Scouts learned from expert Keith Burke that snow avalanches come in different forms. A powder or "sluff" avalanche starts at a single point and fans out as surface snow slides downhill. These avalanches are not as violent as slab avalanches. Slab avalanches are very dangerous. They occur when a whole hillside of snow breaks loose in a giant slab, which then breaks into snow blocks that tumble downhill faster and faster.