Krister Kristensen

Measurements of powder snow avalanche- nature -

Snow cloud growth rates of powder snow avalanche were obtained with analysing the pictures recorded in Ryggfonn, Norway. Although results showed wide scattering, as far as the data obtained in runout zone are concerned, they roughly agreed with the water tank experiments by Beghin and Olagne (1991).Air movement in snow avalanche cloud was measured with an ultra-sonic anemometer in Kurobe Canyon, Japan. It showed rising current existed near the front and downward at the trail. Comparing with drifting snow threshold and particle suspension criterion, entrainment, suspension and deposition of snow particles in the snow cloud were discussed.

Particle simulation of snow avalanche motion

Abstract The continuum model of a snow avalanche is abandoned, and instead an avalanche is modeled as a collection of ∼10 3 particles that move randomly and independently subject to gravity and resistive forces which have a random fluctuation computed by Monte-Carlo simulation. The model includes entrainment at the avalanche front and the possibility of varying resistive parameters with speed and slope position. Particle statistics computed for an avalanche event in Norway, April 1982, provide a reasonable simulation of recorded speeds and debris distribution.