期刊名称：Bulletin of the Geographical Survey Institute
印刷版ISSN：0373-7160
出版年度：2005
卷号：52
出版社：Geographical Survey Institute / Ministry of Land, Infrastructure and Transport
摘要：The occurrence of full-depth snow avalanches (FDSAs) on slopes in Japanese mountain areas is indicated by narrow straight scratch patterns, called "avalanche furrows", on aerial photographs. Avalanche furrows show a semicircular or U-shaped transverse profile as if they had been scored by a round chisel. They have a width of 2-4 m and a depth of 1-3 m and occur mainly on slopes with a 35°-45° inclination. Avalanche furrows are exposed on a smooth surface of bedrock and show striae produced by FDSAs. Aerial-photo interpretation over Japanese Islands shows that avalanche furrows are mainly distributed from Hokkaido to the Chugoku Mountains along the Japan Sea coast. The distribution of avalanche furrows corresponds to mountains with deep snow cover over 2 m and increases with altitude. In other countries, wet snow avalanches occur mainly in polar and alpine areas with much colder climates. In contrast, FDSAs occur in temperate climates and at altitudes as low as 300 m in Japan. The major factors controlling the formation of avalanche furrows in Japan are considered to be the temperate climate, heavy snowfall, steep slopes and poor vegetation.
