Low density/poorly bonded layers within the snowpack (graupels) describe which concept?

• A. Depth hoar
• B. Surface hoar
• C. Facets
• D. Low density/poorly bonded layers within snowpack (graupels)

Answer: (D)

Graupel layers in the snowpack are weak layers: they are low in density and poorly bonded. This happens when snowflakes are rimed by supercooled water droplets, turning into small rounded pellets that don’t interlock tightly with neighboring grains. The result is a loose, weak layer that can fail under load or warmer conditions, making it a common contributor to avalanche release. This stands in contrast to depth hoar, which forms from a strong temperature gradient producing large, faceted crystals at depth, and surface hoar, which deposits on the surface and may be buried later. The key idea is that graupel describes a distinct type of weak, low-density layer within the snowpack that can drive avalanches.