COMPLEX GEOTHERMAL INVESTIGATIONS IN THE BOREHOLE KUN-1 (KUNASHIR ISLAND). PART 1 :VERTICAL TEMPERATURE DISTRIBUTION, HEAT FLOW, TOPOGRAPHY AND HYDROGEOLOGY INFLUENCE, DIURNAL WAVE PROPAGATION
Geothermal investigations in the borehole kun-1 were performed with the aim of complex studying of spatial-temporal thermal field variability in the Southern Kuril Islands. The continuous 16-channel temperature logger was established in the borehole in 2007. Temperature was monitored at different depth with thirty minutes reading interval. The paper describes the first part of these investigations. It is shown that vertical distribution of mean annual temperatures is determined by heat flow, paleoclimate, topography, and water flow influences. Accounting for these factors allows to estimate undisturbed thermal gradient (111,2±2,3 К/xm) and heat flow (189±34 mW/m2). A method is proposed to identification of water flow induced temperature anomalies. The method is based on the anomaly magnitude/shape analysis and allows distinguish water flow localized in limited space (borehole or behind casing space) from the same in porous media. Thermal diffusivity of rocks was determined by analysis of diurnal temperature wave attenuation and phase shift with depth (0,610-6 m^2/s).