温泉地帯における地温勾配の型式について

抄録

Ground water temperature has no relation to the depth, where the water flow speed is so rapid that the water can not be heated with the normal earth temperature gradient and the thermal conductivity. Such a case is seen in the ground water in the northern part of Shimabara City alluvial fan. Where there is hot spring water in the deep formation, the upper layer has a sharp temperature gradient. The temperature gradient in the hot spring layer is almost gentle, which claims there the vertual conductivity, from heat balance rule. Where the deeper layer has constant temperature, it can be explained by the hot water flowing upwards vertically. The negative temperature gradient suggests the constant seepage of lower temperature water. The relation of depth and temperature being not linear, suggests that there is some heat generation or sink. But there can not be expected such facts, so it may be caused by the upwards leakage of hot water through crevices, and flowing horizontally.