Detailed Study on Thermal Conductivity Distribution in Japanese Geothermal Fields

Abstract

Thermal conductivity is an important physical property not only for the study of heat flow but also for many practical problems, which include extracting heat from a hot and dry rock body, However, as far as the actual values of subsurface thermal conductivity distribution for the Japanese Islands are concerned, very few systematic study has been made yet. The authors have measured thermal conductivity of a large number of drill-core samples, as well as some surface rocks in Japanese geothermal fields. In this paper, discussions are made on the relationship between thermal conductivity and other physical properties, in an attempt to obtain a better view of the nationwide distribution of thermal conductivity, which is necessary to convert existing temperature gradient values to heat flow values.