Terrestrial radar interferometry for snow glide activity monitoring and its potential as precursor of wet snow avalanches.

Rafael Caduff, Andreas Wiesmann, Yves Bühler, Claudia Bieler and Philippe Limpach

Snowpack displacement and resulting full depth gliding snow avalanches are a widespread problem in alpine regions during springtime after snow-rich winters. This is a major threat for infrastructures nearby. Today field observers detect gliding snow visually. However, they can only detect suspicious snowpack displacement after gliding cracks opened. Many wet snow avalanches release without formation of visible tension cracks in an early stage so that they appear to happen spontaneously. Terrestrial radar interferometry has recently proven to be an effective method for the detection and monitoring of snow glide activity on a slope scale. Movements of the snowpack less than 0.5 mm/h can be detected as validated with a total station. Detection of snow glide activity is therefore achievable at a very early stage. Continuous measurements with rates of up to one scene per minute allow the immediate assessment of snow glide activity on the monitored slope. Therefore this method might be applied in future to detect precursors for full depth gliding snow avalanches.

2016/1 239-248