1972 Volume 34 Issue 4 Pages 173-186
The observations on the active layer of permafrost were carried out at the summit of Mt. Fuji since 1970. The observational results can be summerized as follows.
The existence of permafrost was confirmed at the summit of Mt. Fuji (3, 776.3m above sea level, 35°21'N, 138°44'E), not only within the small area near the Fuji-san Weather Station where the existence of frozen soil was observed at summer before, but in the whole area of the crater rim of summit.
The lower limit of the existence of permafrost was about 2, 800m at the northern slope and about 2, 900m at the southern slope. The mean annual air temperature at these elevation is -1.4-1.8°C.
Thickness of the active layer of permafrost was 50130cm at the end of July. The active layer was thinner in the area where the deposited snow was deeper in winter. Thickness of the active layer was nearly in proportion to the square root of thawing index after disappearance of the deposited snow.