A large block tested by the weight of a skier to assess initiation and fracture quality.

Credit: Robson Fletcher / Radio-Canada

The Rutschblock Test, or RB, is the largest column test, and thus, the most time consuming to set up. A block the width of a pair of skis (2m wide by 1.5 m upslope) is isolated and loaded in a series of steps as a skier approaches the block, weights, and jumps on the block. Whole blocks that fail early in the loading steps, especially with high fracture quality scores, suggest the slope is unstable. The Rutschblock only tests layers that are deeper than ski penetration and is only reliable for weak layers that are about a meter or less below ski penetration depth. Because a Rutschblock spans a larger area of snow, it is more robust to slope scale spatial variability than smaller column tests, such as the compression test.

Credit: Association Nationale pour l’Étude de la Neige et des Avalanches (ANENA)