Item: Acceleration Processes of Snow Glide Prior to Full-Depth Avalanche Release on Shrub Slopes in the Temperate Heavy-Snow Region of Japan
-
-
Title: Acceleration Processes of Snow Glide Prior to Full-Depth Avalanche Release on Shrub Slopes in the Temperate Heavy-Snow Region of Japan
Proceedings: International Snow Science Workshop 2016 Proceedings, Breckenridge, CO, USA
Authors:
- Katsuhisa Kawashima [ Research Institute for Natural Hazards and Disaster Recovery, Niigata University, Niigata, Japan ]
- Tsutomu Iyobe [ Graduate School of Engineering, Kyoto University, Kyoto, Japan ]
- Takane Matsumoto [ Research Institute for Natural Hazards and Disaster Recovery, Niigata University, Niigata, Japan ]
Date: 2016-10-02
Abstract: In the temperate heavy-snow region of Japan, most of snow avalanche disaster arise as a consequence of the full-depth glide avalanche in the area with human activities. Although snow glide motion of a snow cover on slope is one of the most important factors for full-depth avalanche release, snow glide acceleration processes are still poorly understood, which disturbs improvement of the prediction accuracy. In this study, we were intended to contribute to the accumulation of snow glide data prior to full-depth avalanche release on the shrubby slopes. Measurements of snow glide by glide shoes were made on two slopes covered with deciduous shrubs (3–10 m in height), which is typical vegetation on avalanche-prone slope in Niigata Prefecture, central Japan. Consequently, we observed 3 full-depth avalanche events. Our data showed that snow gliding shifts its motion. It starts with "uniform motion", continues with "constant acceleration motion", then "increasing acceleration motion". The last stage is the most important for avalanche forecasting, because this brings about avalanche release. Further analysis of increasing acceleration stage, it became clear that glide acceleration rate is an increasing function of glide rate and is directly proportional to the square of glide rate. This relation provides a convenient method for estimating the time to avalanche release for snow slab with given glide rate, which seems likely to be applicable to the short-time forecast of full-depth glide avalanches in the future.
Language of Article: English
Presenters:
Keywords: full-depth glide avalanche, snow glide, avalanche release, shrub slope
Page Number(s): 525-532
Subjects: avalanche release full-depth avalanches snow gliding
-
Digital Abstract Not Available
-