Snow avalanches

Each winter key sections of Norwegian road and railway lines are closed, and in extreme winters avalanches and avalanche hazards can lead to several hundred people having to be evacuated from their homes.

An average of five people annually are killed in avalanches in Norway. Whereas in the past people tended to lose their lives in their homes, today there is a growing tendency for fatal accidents to take place in connection with outdoor activities.

NGI's state-of-the-art expertise

  • knowledge of where and when avalanches may occur
  • calculation of the speed, pressure effects and run-out distance of avalanches
  • optimisation of safety measures

Services related to snow avalanches

In 1972 the Storting decided that governmental funded research on avalanches should be assigned to NGI. Our core expertise is knowledge of avalanche mechanisms and the conditions that cause avalanches. Meteorological (precipitation, winds and temperature) and topographical conditions are key factors. NGI has a close working relationship with the Norweh\gian Meteorological Institute.

NGI has its own avalanche research station, Fonnbu, in Grasdalen valley in the Strynefjell mountains, one of Norway's most avalanche-prone areas.  At Fonnbu, empirical data on snow and weather conditions are collected and compiled.  All avalanches in the area are mapped and avalanche warnings are issued for National Highway 15.

Full scale tests are carried out at Ryggfonn, a special test field site where avalanches can be triggered naturally or by dynamite. Instruments are set up to measure the velocity and pressure effects of the avalanche and the effect of a 16 m high catching dam on the valley floor, with measurement of avalanche velocity, force and run-out distance.

NGI assists local authorities in the event of acute avalanche hazards, and takes part each year in the Norwegian Armed Forces - avalanche group in the big NATO winter exercises.

Research and development
The challenges and NGI's research in connection with avalanches are associated with:

  • modelling and calculation of run-out distance and forces
  • full-scale measurement of avalanches at Ryggfonn
  • methods for determining avalanche-prone areas
  • new avalanche warning methods and emergency routines
  • safety measures against avalanches, such as catching dams and snow fences

NGI engages in international projects with expertise from France, Switzerland, Austria, Italy, the USA and Japan.

snoskred.no
NGI has established a special website for outdoor enthusiasts,www.snoskred.no, with current information about avalanche hazards (in the areas where NGI provides these warnings), avalanches that have taken place, snow and weather conditions.  The web site provides links to meteorological data and other relevant websites.

Selected projects and topics