Activities of the Japanese-Norwegian collaboration on snow avalanche research, march 1991

Abstract

The report gives a brief summary of the activities carried out by the Japanese - Norwegian collaboration on snow avalanche reasearch during the winter of 1990/19991. The research was mainly carried out in the Ryggfonn experiment site and at NGI research station in Grasdalen in Ryggfonn. The installation in Ryggfonn were extended by a wind sensor, a seismometer, an air pressure sensor and two video-cameras. One artifically released wet snow avalanche was recorded. The avalanche had a volume of approximately 20.000m3 and a velocity of 25 m/s in the steep part of the path. Snow cover studies were carried out to investigate if there were differencies in the potential sliding layers of the snow pack in Japan and Norway. In addition, theories of the dynamics of granular materials developed in Norway and Japan were compared.