Terrestrial heat flow at Hirabayashi on Awaji Island, south-west Japan

Terrestrial heat flow at Hirabayashi in Awaji Island, south-west Japan, was investigated using the deep borehole penetrating through the Nojima Fault, which was activated during the 1995 Hyogo-ken Nanbu earthquake, by measuri ng the thermal conductivity of basement rocks. Using the temperature loggin g data, the value of terrestrial heat flow in Hirabayashi was found to be 5 6.6 +/- 5.2 mW/m(2). The relationship between cut-off depth of aftershocks of the Hyogo-ken Nanbu earthquake in Hirabayashi and terrestrial heat flow are discussed. The cut-off depth roughly corresponds to isotherms of 300 de greesC.