The abnomally heavy snowfalls in the Tohoku District, Japan during the 1973/74 winter season (November-March) produced some record-breaking snow depths at several meteorological stations, and unusually large amounts of snow in the Japan Sea side mountains were recognized by an airborne photogrametry which was carried out on 6 April 1974.
An example of mean snow depth over a cirque of one kilometer in diameter was 17m, and many drift type snow covers reached 30-50m at niches of 1300-1900m above sea level on the eastern and southern slopes of Mt. Iide (Kitatamata-dake and Onishi-dake), Mt. Gassan and Mt. Chokai (40°N latitude).
Some field surveys show the fact that the critical value of the one ablation season survival is about 30m at the above-mentioned places.
A remnant drift type snow pack at the 1400m height on the southern slope of Mt. Chokai developed into a small niche type glacier after the heavy snowfalls of 1973/74 winter, and the glacier flowed at a rate of 20cm/day during the 1975 summer season.