Trigger Point

Mark Bender

Fracture line linking thin spots

The trigger point is the location where a person or machine initiates an avalanche. Possible trigger points include: 

  • The top of a steep slope; 
  • Thin areas of the snowpack such as a shallow rocky start zone; 
  • Locations where the snowpack has reached critical loading through windloading or new precipitation;
  • Places where a weak layer is especially weak;
  • Places where the snowpack is perforated by rocks or trees. 
  • Combinations of the above

Fracture lines often connect these areas of weakness or increased stress on the snowpack.