ABSTRACT A heat flow measurement technique used in shallow boreholes on the Norwegian Continental Shelf in water depths from 105 to 440 m is described. A thermistor probe was mounted on a downhole jack normally used for geotechnical investigations, and connected to an onboard recording unit via amplifiers and an umbilical cable. Measurements of in-situ temperature in Quaternary sediments were obtained to 70 m below the seabed with a resolution and accuracy of the measured temperatures of 0.008° C and 0.02°C, respectively. In order to establish heat flow values, thermal conductivity was measured on high quality push samples obtained from the depth interval covered by temperature measurements. The method described can be applied in conjunction with normal shallow drilling marine geotechnical programs and thus provides an opportunity for extensive collection of heat flow data to be used in the modelling of present day thermal conditions and fluid flow in offshore sedimentary basins. INTRODUCTION The vast majority of measurements comprising world heat flow data base are confined to either the Abyssal oceans or deep (greater than 500 m) boreholes on land. Largely due to the disturbing effect of bottom water temperature fluctuations in shallow water environments and the general lack of availability of reliable thermal measurements from deep production boreholes, continental margins remain grossly undersampled with respect to heat flow. In light of the increasing attention being given to shallow water sedimentary basin areas by explorationists and petroleum geologists, this appears an unfortunate situation. with this in mind an effort was launched to develop an operationally practical system to obtain heat flow data by measuring temperature and thermal conductivity in Quaternary sediments beneath the seafloor in continental shelf areas. Heat flow data measured as described here has to be subjected to corrections for several effects like isostatic uplift, sedimentation and erosion and late Quaternary temperature fluctuations as described by several authors (i.e. Birch, 1950 and Beck, 1977). This will not be discussed further in the present paper. In the summer of 1985, the Continental Shelf and Petroleum Technology Research Institute (IKU) of Trondheim, Norway performed a stratigraphic bedrock drilling and heat flow programme in the North Norwegian Continental Shelf. The survey was conducted from the geotechnical drill ship M.S. Bucentaur (figure 1). Heat flow values were measured in 9 boreholes with water depths varying between 105 and 440 m. As part of the survey Fugro B.V. of Leidschendam, The Netherlands and Ornegalink International Ltd. of New York, U.S.A. were subcontracted to perform temperature measurements in the Quaternary sediments and to measure thermal conductivity on samples recovered from corresponding levels in the boreholes. Vertical conductive heat flow through the underground can be described by the following equation: (Mathematical equation available in full paper)