Question

Into which two main types are snow avalanches broadly categorized?

• A. Winter snow avalanches and Summer snow avalanches
• B. Fast-moving avalanches and Slow-moving avalanches
• C. Dry snow avalanches and Wet snow avalanches
• D. Small-scale avalanches and Large-scale avalanches

Answer 1

Answer:

C. Dry snow avalanches and Wet snow avalanches

Snow avalanches are broadly categorized into two main types based on their moisture content:

1. Dry Snow Avalanches:

   • Characteristics: These occur in cold conditions with loose, powdery, or well-bonded but dry snow.

   • Movement: They can be very fast, often generating a large "powder cloud" above the main flowing mass of snow.

   • Danger: Dry slab avalanches (a common type of dry avalanche) are particularly dangerous and account for a high percentage of avalanche fatalities, as they can be triggered by relatively light loads and fracture a large area.

2. Wet Snow Avalanches:

   • Characteristics: These occur when the snowpack is moist or saturated with water, often due to warming temperatures, sun, or rain.

   • Movement: They tend to be slower and denser than dry avalanches, moving more like a viscous fluid.

   • Danger: While generally slower, their high density and mass can still be extremely destructive, capable of carrying large debris and causing significant damage to infrastructure and vegetation. They can be hard to forecast as water takes time to penetrate the snowpack.