Investigation of temperature variations in borehole Kun-1 (Kunashir Island)

The data of temperature monitoring in boreholes revealed significant nonstationary properties of the Earths thermal field, which is pronounced at all depths and in a wide time range: from a few seconds to a few years [17]. The nonstationary component of the thermal field is caused by natural physical pro cesses (climatic, meteorological, phase transition, hydrogeological, tidal, tectonic, and seismic phenom ena) occurring in the space around the boreholes and by the thermal processes related to the borehole con struction and the system of measurements (free ther mal convection, intra borehole and behind casing water flows). Insignificant temperature fluctuations(0.010.001 K) caused by the intra borehole convec tion are noises, for example in the estimation of the thermal flux. At the same time, they contain valuable information about the behavior of fluids in the bore hole [1, 2, 8]. The tidal component of temperature variations is an information carrier about the deform ing properties of the system boreholeunderground water reservoir.