  The thermal conductivity of the methane hydrate CH4 (5.75 H2O) was measured
in the interval 2-140 K using the steady-state technique. The thermal
conductivity corresponding to a homogeneous substance was calculated from the
measured effective thermal conductivity obtained in the experiment. The
temperature dependence of the thermal conductivity is typical for the thermal
conductivity of amorphous solids. It is shown that after separation of the
hydrate into ice and methane, at 240 K, the thermal conductivity of the ice
exhibits a dependence typical of heavily deformed fine-grain polycrystal. The
reason for the glass-like behavior in the thermal conductivity of clathrate
compounds has been discussed. The experimental results can be interpreted
within the phenomenological soft-potential model with two fitting parameters.
