A narrow column test for identifying and testing crack initiation and fracture quality in the upper snowpack.
A Compression Test, or CT, is a narrow column test that allows someone to identify and test the propensity for crack initiation in weak layers in the upper snowpack. An incremental load is applied to an isolated column (30 cm by 30 cm) to observe both the amount of force required to initiate failure as well as the shear quality or character of the failure. Easy initiation, and more importantly clean, sudden fractures, are indicative of poor stability. The test is one of the easiest and fastest to conduct. However, it has limitations because it only tests a small column of snow, relative to other large column tests. Loading steps are the same as the ECT: 10 taps onto a shovel blade from the wrist, 10 from the elbow, and 10 from the shoulder.