The basic principles on snow and avalanches (with regard to the practical application for mountaineers and backcountry skiers) were already set up in the 1920s and 1930s.Snow classification and the classification of the snow hardness (both developed in the following decades) were also used by many mountaineers and backcountry skiers, and these classifications still play an essential part in evaluating the prevailing avalanche situation (see for example Schweizer 2006 The Nietentest ). The snow classification standardised snow profile investigations; the hardness classification is an important tool for the assessment of the varying layers in the snowpack. However, hardness measurements with the Swiss Rammsonde cannot be applied by backcountry skiers. The classifications help to get a better overview of the structure of the snowpack and to estimate the current avalanche danger, although snow profiles do not give any information about the bonding of the different layers.
