Abstract
A new type of device for the measurements of the maximum depth of frozen ground was developed. The maximum depth D was calculated from the decrease in the amount of water in a transparent plastic pipe, following a theoretical equation :
D= ρw/ρw-ρi· S'/Sd=kd
Where ρw and ρi are the density of water and ice, S' and S the effective cross section areas of the top and bottom part of the plastic pipe, and d is the decrease of water denoted by the length (Fig. 2).
Using this device and a general depth meter the depth of frost penetration were observed at the test pits at Akan in Hokkaido, between 1973-1977. The value obtained using these devices wasalmost equal.
