Preliminary Results from Underwater Boreholes on Lake Reliability of Geothermal Measurements

Abstract

Geothermal measurements in two m deep underwater boreholes in Baikal E) yielded a thermal gradient of 41 and average heat flow of 73 These values are different from earlier shallow measurements. The downhole temperature taken at depths 28, 58, and 88 m sub-bottom showed an increase with depth from 3.41 to Thermal conductivity determined by needle probe on samples immediately after the core recovery tends to be lower than that measured on 553 samples several weeks later in the laboratory (1.16 against 1.76 The systematic difference of about 30%between the two methods may be due the effect of outgassing and consolidation of sediments. A sound resolution of the questions can be obtained by repeated measurements in underwater boreholes to be in1995 - 1997.