Heat transfer in the seasonal active layer of Gorshkov Ice Cap on the summit of Ushkovsky Volcano, Kamchatka Peninsula

Seasonal heat and mass transfer in the cold snow-accumulation area of Gorshkov Ice Cap (3903 m a.s.l.) on Ushkovsky Volcano is studied on the basis of model simulations to interpret continuous two-year temperature records from seven thermistors installed in the 27-meter deep borehole. Precipitation seasonality, relatively high annual accumulation rates, and snow-firn densification are found to be the principal peculiarities of the process. Only first harmonics of the seasonal temperature variations were significant and reliably detectable. The amplitude of the surface-temperature fluctuations is inferred to be 16.6 degree C. The mean annual surface temperature of 1996 is determined as -17.5 degree C with a short-term trend about -2.3 degree C yr delta uring the 1996-1998 period. The relative thermal conductivity of snow and firn A as a parametric function of porosity c is simultaneously verified with the parameter a approximately 0.5 (see Table l). The impact of the interaction between the seasonal variations of the surface temperature and the mass balance rate on the thermal state of the glacier below the active layer is theoretically estimated as very small.